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{{Short description|Vaccine that protects against yellow fever}}
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{{Use dmy dates|date=November 2022}}
{{Use British English|date=November 2020}}
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| image =Barros inaugura linha de produção da vacina de febre amarela (28118409009).jpg

| caption= Yellow fever vaccine vials (Brazil)
<!--Vacine data-->
<!-- Vaccine data -->
| type = vaccine
| type = vaccine
| target = Yellow fever
| target = Yellow fever
| vaccine_type = Attenuated
| vaccine_type = attenuated
<!-- Clinical data -->

| tradename = YF-Vax, Stamaril
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| tradename =
| synonyms = 17D vaccine
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| legal_UK_comment = <ref>{{cite web | title=Stamaril powder and solvent for suspension for injection in pre-filled syringe - Summary of Product Characteristics (SmPC) | website=(emc) | date=9 September 2019 | url=https://www.medicines.org.uk/emc/product/1683/smpc | access-date=28 December 2019}}</ref>
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| routes_of_administration = Subcutaneous injection
| routes_of_administration = Subcutaneous injection
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<!-- Definition and medical uses -->
'''Yellow fever vaccine ''' is a [[vaccine]] used against [[yellow fever]].<ref name="pmid18431480">{{cite journal |author=Roukens AH, Vossen AC, Bredenbeek PJ, van Dissel JT, Visser LG |editor1-last=Von Seidlein |editor1-first=Lorenz |title=Intradermally administered yellow fever vaccine at reduced dose induces a protective immune response: a randomized controlled non-inferiority trial |journal=PLoS ONE |volume=3 |issue=4 |pages=e1993 |year=2008 |pmid=18431480 |pmc=2297511 |doi=10.1371/journal.pone.0001993 |url=http://www.plosone.org/article/info:doi/10.1371/journal.pone.0001993}}</ref><ref name="pmid18039952">{{cite journal |author=Norrby E |title=Yellow fever and Max Theiler: the only Nobel Prize for a virus vaccine |journal=J. Exp. Med. |volume=204 |issue=12 |pages=2779–84 |year=2007 |month=November |pmid=18039952 |pmc=2118520 |doi=10.1084/jem.20072290 |url=http://www.jem.org/cgi/pmidlookup?view=long&pmid=18039952}}</ref>
'''Yellow fever vaccine ''' is a [[vaccine]] that protects against [[yellow fever]].<ref name="WHO2013">{{cite journal |vauthors=((World Health Organization)) |author-link=World Health Organization |date=July 2013 |title=Vaccines and vaccination against yellow fever. WHO position paper -- June 2013 |journal=Weekly Epidemiological Record |volume=88 |issue=27 |pages=269–283 |pmid=23909008 | hdl=10665/242089 | hdl-access=free }}</ref> Yellow fever is a viral infection that occurs in [[Africa]] and [[South America]].<ref name=WHO2013/> Most people begin to develop immunity within ten days of vaccination and 99% are protected within one month, and this appears to be lifelong.<ref name=WHO2013/> The vaccine can be used to control outbreaks of disease.<ref name=WHO2013/> It is given either by [[intramuscular|injection into a muscle]] or [[subcutaneous injection|just under the skin]].<ref name=WHO2013/><ref name="sciencedirect.com">{{Cite web |title=Yellow Fever Vaccine - an overview {{!}} ScienceDirect Topics |url=https://www.sciencedirect.com/topics/nursing-and-health-professions/yellow-fever-vaccine |access-date=30 April 2022 |website=www.sciencedirect.com}}</ref>


<!-- Recommendations -->
The vaccine consists of a live, but attenuated, strain of the yellow fever virus called 17D. The 17D vaccine has been used commercially since the 1950s. The mechanisms of attenuation and [[immunogenicity]] for the 17D strain are not known. However, this vaccine is very safe, with few adverse reactions having been reported and millions of doses administered, and highly effective with over 90% of vaccinees developing a measurable immune response after the first dose. Yellow fever vaccination certificate is issued for 10 years but becomes valid only after 10 days of vaccination.<ref>http://www.sticholidays.com/sticholidays/india/yellowfever.php</ref>
The [[World Health Organization]] (WHO) recommends [[vaccination schedule|routine immunization]] in all countries where the disease is common.<ref name=WHO2013/> This should typically occur between nine and twelve months of age.<ref name=WHO2013/> Those traveling to areas where the disease occurs should also be immunized.<ref name=WHO2013/> Additional doses after the first are generally not needed.<ref>{{cite journal | vauthors = Staples JE, Bocchini JA, Rubin L, Fischer M | title = Yellow Fever Vaccine Booster Doses: Recommendations of the Advisory Committee on Immunization Practices, 2015 | journal = MMWR. Morbidity and Mortality Weekly Report | volume = 64 | issue = 23 | pages = 647–650 | date = June 2015 | pmid = 26086636 | pmc = 4584737 }}</ref>

<!-- Safety -->
The yellow fever vaccine is generally safe.<ref name=WHO2013/> This includes in those with [[HIV infection]] but without symptoms.<ref name=WHO2013/> Mild side effects may include [[headache]], muscle pains, pain at the injection site, [[fever]], and rash.<ref name=WHO2013/> [[Anaphylaxis|Severe allergies]] occur in about eight per million doses, serious neurological problems occur in about four per million doses, and [[organ failure]] occurs in about three per million doses.<ref name=WHO2013/> It appears to be safe in [[pregnancy]] and is therefore recommended among those who will be potentially exposed.<ref name=WHO2013/> It should not be given to those with [[immunosupressed|very poor immune function]].<ref name=CDC2011>{{cite web|title=Yellow Fever Vaccine|url=https://www.cdc.gov/yellowfever/vaccine/|publisher=[[Centers for Disease Control and Prevention]] (CDC)|access-date=15 December 2015|date=13 December 2011|url-status=live|archive-url=https://web.archive.org/web/20151209174457/http://www.cdc.gov/yellowfever/vaccine/|archive-date=9 December 2015}}</ref>

<!-- History, society and culture -->
Yellow fever vaccine came into use in 1938.<ref name=Nor2007>{{cite journal | vauthors = Norrby E | title = Yellow fever and Max Theiler: the only Nobel Prize for a virus vaccine | journal = The Journal of Experimental Medicine | volume = 204 | issue = 12 | pages = 2779–2784 | date = November 2007 | pmid = 18039952 | pmc = 2118520 | doi = 10.1084/jem.20072290 }}</ref> It is on the [[WHO Model List of Essential Medicines|World Health Organization's List of Essential Medicines]].<ref name="WHO21st">{{cite book | vauthors = ((World Health Organization)) | title = World Health Organization model list of essential medicines: 21st list 2019 | year = 2019 | hdl = 10665/325771 | author-link = World Health Organization | publisher = World Health Organization | location = Geneva | id = WHO/MVP/EMP/IAU/2019.06. License: CC BY-NC-SA 3.0 IGO | hdl-access=free }}</ref><ref name="WHO22nd">{{cite book | vauthors = ((World Health Organization)) | title = World Health Organization model list of essential medicines: 22nd list (2021) | year = 2021 | hdl = 10665/345533 | author-link = World Health Organization | publisher = World Health Organization | location = Geneva | id = WHO/MHP/HPS/EML/2021.02 | hdl-access=free }}</ref> The vaccine is made from weakened yellow fever virus.<ref name=WHO2013/> Some countries require a [[Carte Jaune|yellow fever vaccination certificate]] before entry from a country where the disease is common.<ref name=WHO2013/><ref name="sciencedirect.com"/>

==Medical uses==
[[File:Soviet International Certificate of Vaccination or Revaccination Against Yello Fever.jpg|thumb|A yellow fever vaccination certificate issued by the [[Soviet Union]].]]

===Targeting===
Medical experts recommend vaccinating people most at risk of contracting the virus, such as woodcutters working in tropical areas.<ref>{{Cite web |title=How WHO is supporting ongoing vaccination efforts during the COVID-19 pandemic |url=https://www.who.int/news-room/feature-stories/detail/how-who-is-supporting-ongoing-vaccination-efforts-during-the-covid-19-pandemic |access-date=28 April 2022 |website=www.who.int |language=en}}</ref> [[Insecticide]]s, protective clothing, and screening of houses are helpful, but not always sufficient for mosquito control; medical experts recommend using personal insecticide spray in endemic areas.<ref>{{cite journal | vauthors = Okumu FO, Moore SJ | title = Combining indoor residual spraying and insecticide-treated nets for malaria control in Africa: a review of possible outcomes and an outline of suggestions for the future | journal = Malaria Journal | volume = 10 | issue = 1 | pages = 208 | date = July 2011 | pmid = 21798053 | pmc = 3155911 | doi = 10.1186/1475-2875-10-208 | doi-access = free }}</ref> In affected areas, [[mosquito control]] methods have proven effective in decreasing the number of cases.<ref>{{cite web |url=http://www.epa.gov/pesticides/health/mosquitoes/mosquitojoint.htm#programs |title=Joint Statement on Mosquito Control in the United States from the U.S. Environmental Protection Agency (EPA) and the U.S. Centers for Disease Control and Prevention (CDC) |access-date=25 June 2006 |date=3 May 2000 |publisher=Environmental Protection Agency |url-status=live |archive-url=https://web.archive.org/web/20061010172101/http://www.epa.gov/pesticides/health/mosquitoes/mosquitojoint.htm#programs |archive-date=10 October 2006 }}</ref>

Travellers need to have the vaccine ten days prior to being in an endemic area in order to assure full immunity.<ref name="WHO Travel and Health"/>{{rp|45}}

===Duration and effectiveness===

For most people, the vaccine remains effective permanently. People who are [[HIV positive]] at vaccination can benefit from a booster after ten years.<ref>{{cite journal |vauthors=Schnyder JL, de Jong HK, Bache BE, Schaumburg F, Grobusch MP |title=Long-term immunity following yellow fever vaccination: a systematic review and meta-analysis |journal=Lancet Glob Health |volume= 12|issue= 3|pages= e445–e456|date=January 2024 |pmid=38272044 |doi=10.1016/S2214-109X(23)00556-9 |s2cid=267128946 |doi-access=free }}</ref>

On 17 May 2013, the World Health Organization (WHO) [[Strategic Advisory Group of Experts|Strategic Advisory Group of Experts on immunization]] (SAGE) announced that a booster dose of yellow fever (YF) vaccine, ten years after a primary dose, is not necessary.<ref>{{Cite web |title=Strategic Advisory Group of Experts on Immunization (SAGE) |url=https://www.who.int/groups/strategic-advisory-group-of-experts-on-immunization |access-date=28 April 2022 |website=www.who.int |language=en}}</ref> Since yellow fever vaccination began in the 1930s, only 12 known cases of yellow fever post-vaccination have been identified, after 600 million doses have been dispensed.<ref>{{Cite web |title=Yellow fever vaccination booster not needed |url=https://www.who.int/news/item/17-05-2013-yellow-fever-vaccination-booster-not-needed |access-date=28 April 2022 |website=www.who.int |language=en}}</ref> Evidence showed that among this small number of "vaccine failures", all cases developed the disease within five years of vaccination.<ref>{{Cite web |title=Vaccine Failure - an overview {{!}} ScienceDirect Topics |url=https://www.sciencedirect.com/topics/neuroscience/vaccine-failure |access-date=28 April 2022 |website=www.sciencedirect.com}}</ref> This demonstrates that immunity does not decrease with time.<ref>{{cite press release|title=Vaccines|url=https://www.who.int/mediacentre/news/releases/2013/yellow_fever_20130517/en/|url-status=dead|archive-url=https://web.archive.org/web/20130609154615/http://www.who.int/mediacentre/news/releases/2013/yellow_fever_20130517/en/|archive-date=9 June 2013|publisher=[[World Health Organization]] (WHO)}}</ref>

===Schedule===
The World Health Organization recommends the vaccine between the ages of 9 and 12 months in areas where the disease is common.<ref name=WHO2013/> Anyone over the age of nine months who has not been previously immunized and either lives in or is traveling to an area where the disease occurs should also be immunized.<ref name=WHO2013/>

==Side effects==
The yellow fever 17D vaccine is considered safe, with over 500 million doses given and very few documented cases of vaccine associated illness (62 confirmed cases and 35 deaths as of January 2019).<ref>{{cite web|title=What are the risks of dying from having the yellow fever vaccine?|url=https://www.newscientist.com/article/2190439-what-are-the-risks-of-dying-from-having-the-yellow-fever-vaccine/|date=11 January 2019}}</ref> In no case of vaccine-related illness has there been evidence of the virus reverting to a virulent phenotype.{{medcn|date=December 2019}}<ref>{{cite journal | vauthors = Harvey WT, Carabelli AM, Jackson B, Gupta RK, Thomson EC, Harrison EM, Ludden C, Reeve R, Rambaut A, Peacock SJ, Robertson DL | title = SARS-CoV-2 variants, spike mutations and immune escape | journal = Nature Reviews. Microbiology | volume = 19 | issue = 7 | pages = 409–424 | date = July 2021 | pmid = 34075212 | doi = 10.1038/s41579-021-00573-0 | pmc = 8167834 }}</ref>

The majority of adverse reactions to the 17D vaccine result from allergic reaction to the eggs in which the vaccine is grown.<ref>{{cite journal | vauthors = Rutkowski K, Ewan PW, Nasser SM | title = Administration of yellow fever vaccine in patients with egg allergy | journal = International Archives of Allergy and Immunology | volume = 161 | issue = 3 | pages = 274–278 | date = 2013 | pmid = 23548550 | doi = 10.1159/000346350 | s2cid = 25697965 }}</ref> Persons with known [[egg allergy]] should discuss this with their physician prior to vaccination.<ref>{{Cite web |last=CDC |date=10 December 2021 |title=Flu Vaccine and People with Egg Allergies |url=https://www.cdc.gov/flu/prevent/egg-allergies.htm |access-date=28 April 2022 |website=Centers for Disease Control and Prevention |language=en-us}}</ref> In addition, there is a small risk of [[neurologic disease]] and [[encephalitis]], particularly in individuals with compromised [[immune system]]s and very young children. The 17D vaccine is [[contraindicated]] in (among others) infants between zero and six months,<ref>{{cite web|title=Yellow Fever Vaccine Information Statement |publisher=U.S. [[Centers for Disease Control and Prevention]] (CDC) |url=https://www.cdc.gov/vaccines/hcp/vis/vis-statements/yf.html |url-status=live|archive-url=https://web.archive.org/web/20130921061606/http://www.cdc.gov/vaccines/hcp/vis/vis-statements/yf.html |archive-date=21 September 2013|date=April 2020 }}</ref> people with [[thymus]] disorders associated with abnormal immune cell function, people with primary immunodeficiencies, and anyone with a diminished immune capacity including those taking [[immunosuppressant drugs]].<ref>{{cite web|title=Yellow Fever|publisher=[[Centers for Disease Control and Prevention]] (CDC)|url=http://wwwnc.cdc.gov/travel/yellowbook/2012/chapter-3-infectious-diseases-related-to-travel/yellow-fever.htm#1977|url-status=live|archive-url=https://web.archive.org/web/20130116070149/http://wwwnc.cdc.gov/travel/yellowbook/2012/chapter-3-infectious-diseases-related-to-travel/yellow-fever.htm#1977|archive-date=16 January 2013}}</ref>

There is a small risk of more severe yellow fever-like disease associated with the vaccine. This reaction, known as yellow fever vaccine-associated acute viscerotropic disease (YEL-AVD),<ref name="pmid18419548">{{cite journal | vauthors = Bae HG, Domingo C, Tenorio A, de Ory F, Muñoz J, Weber P, Teuwen DE, Niedrig M | title = Immune response during adverse events after 17D-derived yellow fever vaccination in Europe | journal = The Journal of Infectious Diseases | volume = 197 | issue = 11 | pages = 1577–1584 | date = June 2008 | pmid = 18419548 | doi = 10.1086/587844 | doi-access = free }}</ref> causes a fairly severe disease closely resembling yellow fever caused by [[virulent]] strains of the virus.<ref>{{Cite web |title=Yellow fever |url=https://www.who.int/news-room/fact-sheets/detail/yellow-fever |access-date=28 April 2022 |website=www.who.int |language=en}}</ref> The risk factors for YEL-AVD are not known, although it has been suggested that it may be genetic.<ref>{{cite journal | vauthors = Rafferty E, Duclos P, Yactayo S, Schuster M | title = Risk of yellow fever vaccine-associated viscerotropic disease among the elderly: a systematic review | journal = Vaccine | volume = 31 | issue = 49 | pages = 5798–5805 | date = December 2013 | pmid = 24079979 | doi = 10.1016/j.vaccine.2013.09.030 }}</ref> The [[2'-5'-oligoadenylate synthase]] (OAS) component of the [[innate immune response]] has been shown to be particularly important in protection from [[Flavivirus]] infection.<ref>{{cite journal | vauthors = Deo S, Patel TR, Dzananovic E, Booy EP, Zeid K, McEleney K, Harding SE, McKenna SA | title = Activation of 2' 5'-oligoadenylate synthetase by stem loops at the 5'-end of the West Nile virus genome | journal = PLOS ONE | volume = 9 | issue = 3 | pages = e92545 | date = 20 March 2014 | pmid = 24651762 | pmc = 3961380 | doi = 10.1371/journal.pone.0092545 | bibcode = 2014PLoSO...992545D | doi-access = free }}</ref> Another reaction to the yellow fever vaccine is known as yellow fever vaccine-associated acute neurotropic disease (YEL-AND).<ref>{{cite journal | vauthors = Florczak-Wyspiańska J, Nawotczyńska E, Kozubski W | title = Yellow fever vaccine-associated neurotropic disease (YEL-AND) - A case report | journal = Neurologia I Neurochirurgia Polska | volume = 51 | issue = 1 | pages = 101–105 | date = January 2017 | pmid = 27707454 | doi = 10.1016/j.pjnns.2016.09.002 }}</ref>

The Canadian Medical Association published a 2001 CMAJ article entitled "Yellow fever vaccination: be sure the patient needs it".<ref>{{cite journal | vauthors = Weir E | title = Yellow fever vaccination: be sure the patient needs it | journal = CMAJ | volume = 165 | issue = 7 | pages = 941 | date = October 2001 | pmid = 11599337 | pmc = 81520 }}</ref> The article begins by stating that of the seven people who developed system failure within two to five days of the vaccine in 1996–2001, six died "including 2 who were vaccinated even though they were planning to travel to countries where yellow fever has never been reported."<ref>{{Cite web |title=Yellow fever |url=http://www.kidney.de/bdom/Yellow%20fever.php |access-date=28 April 2022 |website=www.kidney.de}}</ref> The article cites that "3 demonstrated histopatholic changes consistent with wild yellow fever virus."<ref>{{Cite journal | vauthors = Wezam T | journal = Academia.edu |title=Where are the Scientists of World Health Organization |url=https://www.academia.edu/36969670}}</ref> The author recommends vaccination for only non-contraindicated travelers (see the articles list) and those travelers going where yellow fever activity is reported or in the endemic zone which can be found mapped at the CDC website cited below.<ref>{{Cite web |title=Yellow Fever in Nigeria - Alert - Level 2, Practice Enhanced Precautions - Travel Health Notices {{!}} Travelers' Health |url=https://wwwnc.cdc.gov/travel/notices/alert/yellow-fever-nigeria |access-date=28 April 2022 |website=wwwnc.cdc.gov}}</ref> In addition, the 2010 online edition of the Center for Disease Control Traveler's Health Yellow Book states that between 1970 and 2002 only "nine cases of yellow fever were reported in unvaccinated travelers from the United States and Europe who traveled" to West Africa and South America, and 8 of the 9 died.<ref>{{cite journal | title = Updated recommendations for isolation of persons with mumps | journal = MMWR. Morbidity and Mortality Weekly Report | volume = 57 | issue = 40 | pages = 1103–1105 | date = October 2008 | pmc = 7150274 | doi = 10.1016/B978-070203481-7.50007-4 | pmid = 18846033 | author1 = Centers for Disease Control Prevention (CDC) }}</ref> However, it goes on to cite "only 1 documented case of yellow fever in a vaccinated traveler.<ref>{{Cite web |title=Yellow Fever - Chapter 4 - 2020 Yellow Book {{!}} Travelers' Health {{!}} CDC |url=https://wwwnc.cdc.gov/travel/yellowbook/2020/travel-related-infectious-diseases/yellow-fever |access-date=2022-04-28 |website=wwwnc.cdc.gov |language=en-us}}</ref> This nonfatal case occurred in a traveler from Spain who visited several West African countries in 1988".<ref>{{cite book | vauthors = Gershman M, Schroeder B, Staples JE | chapter = Yellow Fever | veditors = Brunette GW |title=Yellow Book: CDC Health Information for International Travel 2012. |date=June 2011 |publisher=Oxford University Press, Incorporated |location=New York |isbn=978-0-19-976901-8 | chapter-url = |url=http://wwwnc.cdc.gov/travel/yellowbook/2010/chapter-2/yellow-fever.htm |archive-url=https://web.archive.org/web/20110701160004/http://wwwnc.cdc.gov/travel/yellowbook/2010/chapter-2/yellow-fever.htm |archive-date=1 July 2011 |url-status=live }}</ref>


==History==
==History==
African tropical cultures had adopted burial traditions in which the deceased were buried near their habitation, including those who died of Yellow fever.<ref>{{cite book | vauthors = Kerr JA, Downs WG | date = 1956 | title = Last refuge of Yellow Fever |url= https://unesdoc.unesco.org/ark:/48223/pf0000068636 |access-date=28 April 2022 }}</ref> This ensured that people within these cultures gained immunity through a childhood case of "endemic" yellow fever through [[acquired immunity]]. This led to a lasting misperception first by colonial authorities and foreign medical experts that Africans have a "natural immunity"<ref>{{Cite web |date=6 April 2022 |title=Types of Immunity to a Disease {{!}} CDC |url=https://www.cdc.gov/vaccines/vac-gen/immunity-types.htm |access-date=24 April 2022 |website=www.cdc.gov |language=en-us}}</ref> to the illness. In the nineteenth century health provisioners forced abandonment of these traditional burial traditions, leading to local populations dying of yellow fever as frequently as those without such burial customs such as settler populations.<ref>{{cite book | vauthors = Watts S |title=Epidemics and History: Disease, Power, and Imperialism |date=1997 |publisher=Yale University Press |location=New Haven |isbn=0-300-07015-2 |page=234}}</ref>
In 1937, [[Max Theiler]], working at the [[Rockefeller Foundation]], developed a safe and highly efficacious [[vaccine]] for yellow fever<ref name="urlMax Theiler - Biography">{{cite web |url=http://nobelprize.org/nobel_prizes/medicine/laureates/1951/theiler-bio.html |title=Max Theiler - Biography |work= |accessdate=2009-01-15}}</ref> that gives a ten-year or more immunity from the virus. For his work on the yellow fever vaccine, he received the 1951 Nobel Prize in Physiology or Medicine.


The first modern attempts to develop a yellow fever vaccine followed the opening of the [[Panama Canal]] in 1912, which increased global exposure to the disease.<ref name=Frierson2010>{{cite journal | vauthors = Frierson JG | title = The yellow fever vaccine: a history | journal = The Yale Journal of Biology and Medicine | volume = 83 | issue = 2 | pages = 77–85 | date = June 2010 | pmid = 20589188 | pmc = 2892770 }}</ref> The Japanese bacteriologist [[Hideyo Noguchi]] led investigations for the [[Rockefeller Foundation]] in [[Ecuador]] that resulted in a vaccine based on his theory that the disease was caused by a [[Leptospira|leptospiral bacterium]].<ref name=Frierson2010/> However, other investigators could not duplicate his results and the ineffective vaccine was eventually abandoned.{{cn|date=September 2022}}
==Risks==
Although the vaccine is considered safe, there are risks involved.


Another vaccine was developed from the "French strain" of the virus, obtained by [[Pasteur Institute]] scientists from a man in Dakar, Senegal, who survived his bout with the disease.{{citation needed|date=April 2022}} This vaccine could be administered by [[scarification]], like the [[smallpox vaccine]], and was given in combination to produce immunity to both diseases, but it also had severe systemic and neurologic complications in a few cases.<ref>{{cite journal | vauthors = Langley JM, Aoki F, Ward BJ, McGeer A, Angel JB, Stiver G, Gorfinkel I, Shu D, White L, Lasko B, Dzongowski P, Papp K, Alexander M, Boivin G, Fries L | title = A nasally administered trivalent inactivated influenza vaccine is well tolerated, stimulates both mucosal and systemic immunity, and potentially protects against influenza illness | journal = Vaccine | volume = 29 | issue = 10 | pages = 1921–1928 | date = February 2011 | pmid = 21219987 | doi = 10.1016/j.vaccine.2010.12.100 }}</ref> Attempts to attenuate the virus used in the vaccine failed. Scientists at the Rockefeller Foundation developed another vaccine derived from the serum of an African named Asibi in 1927, the first isolation of the virus from a human.<ref>{{cite journal| vauthors = Stokes A, Bauer JH, Hudson NP |title=Experimental transmission of yellow fever to laboratory animals|journal=Am J Trop Med Hyg|date=1928|volume=8|issue=2|pages=103–104|doi=10.4269/ajtmh.1928.s1-8.103}}</ref> It was safer but involved the use of large amounts of human serum, which limited widespread use.<ref>{{Cite web |title=Blood safety and availability |url=https://www.who.int/news-room/fact-sheets/detail/blood-safety-and-availability |access-date=28 April 2022 |website=www.who.int |language=en}}</ref> Both vaccines were in use for several years, the Rockefeller vaccine in the Western hemisphere and England, and the Pasteur Institute vaccine in France and its African colonies.<ref>{{cite journal | vauthors = Hajj Hussein I, Chams N, Chams S, El Sayegh S, Badran R, Raad M, Gerges-Geagea A, Leone A, Jurjus A | title = Vaccines Through Centuries: Major Cornerstones of Global Health | journal = Frontiers in Public Health | volume = 3 | pages = 269 | date = 2015 | pmid = 26636066 | doi = 10.3389/fpubh.2015.00269 | pmc = 4659912 | doi-access = free }}</ref>
The majority of adverse reactions to the 17D vaccine result from allergic reaction to the eggs in which the vaccine is grown. Persons with a known [[egg allergy]] should discuss this with their physician prior to vaccination. In addition, there is a small risk of [[neurologic disease]] and [[encephalitis]], particularly in individuals with compromised [[immune system]]s and very young children. The 17D vaccine is [[contraindicated]] in infants, pregnant women, breast-feeding women<ref>{{cite journal|journal=MMWR Morb Mortal Wkly Rep|year=2010|volume=59|issue=5|pages=130&ndash;2|title=Transmission of yellow fever vaccine virus through breast-feeding&mdash;Brazil, 2009|author=Centers for Disease Control and Prevention|pmid=20150888}}</ref> and anyone with a diminished immune capacity, including those taking [[immunosuppressant drugs]].


In 1937, [[Max Theiler]], working with Hugh Smith and Eugen Haagen at the [[Rockefeller Foundation]] to improve the vaccine from the "Asibi" strain, discovered that a favorable chance mutation in the attenuated virus had produced a highly effective strain that was named 17D.<ref name=Frierson2010/> Following the work of [[Ernest Goodpasture]], Theiler used chicken eggs to culture the virus. After field trials in Brazil, over one million people were vaccinated by 1939, without severe complications.<ref name=Nor2007/> This vaccine was widely used by the U.S. Army during World War II.<ref name=mcneill>{{cite journal| vauthors = McNeill JR |title=Yellow Jack and Geopolitics: Environment, Epidemics, and the Struggles for Empire in the American Tropics, 1650–1825 |journal=OAH Magazine of History |date=1 April 2004 |volume=18 |issue=3 |pages=9–13 |doi= 10.1093/maghis/18.3.9 |url= http://maghis.oxfordjournals.org/content/18/3/9.extract|url-status=live|archive-url=https://web.archive.org/web/20161220090052/http://maghis.oxfordjournals.org/content/18/3/9.extract|archive-date=20 December 2016}}</ref> For his work on the yellow fever vaccine, Theiler received the 1951 Nobel Prize in Physiology or Medicine.<ref name="urlMax Theiler - Biography">{{cite web |url=http://nobelprize.org/nobel_prizes/medicine/laureates/1951/theiler-bio.html |title=Max Theiler – Biography |access-date=15 January 2009 |url-status=live |archive-url=https://web.archive.org/web/20090120225816/http://nobelprize.org/nobel_prizes/medicine/laureates/1951/theiler-bio.html |archive-date=20 January 2009 }}</ref> Only the 17D vaccine remains in use today.<ref name=WHO2013/>
According to the travel clinic at the University of Utah Hospital, the vaccine presents an increased risk of adverse reaction in adults aged 60 and older, with the risk increasing again after age 65, and again after age 70. The reaction is capable of producing multiple organ failure and should be evaluated carefully by a qualified health professional before being administered to the elderly.


Theiler's vaccine was responsible for the largest outbreak of [[Hepatitis B]] in history: infecting 330,000 soldiers and giving 50,000 jaundice between 1941 and 1942.<ref>{{cite news |title=World War II Hepatitis Outbreak Was Biggest in History |url=https://apnews.com/article/ce911d4f173f1c8ade810969005b9e57 |work=Associated Press |date=16 April 1987}}</ref> At the time, chronic infectious hepatitis was not known, so when human serum was used in vaccine preparation, serum drawn from a chronic Hepatitis B Virus (HBV) carrier would contaminate the Yellow Fever Vaccine.<ref>{{Cite web |title=Hepatitis B |url=https://www.who.int/news-room/fact-sheets/detail/hepatitis-b |access-date=28 April 2022 |website=www.who.int |language=en}}</ref> In 1941, researchers at [[Rocky Mountain Laboratories]] developed a safer alternative, an "aqueous-base" version of the 17D vaccine using distilled water combined with the virus grown in chicken eggs.<ref name="Hettrick">{{cite journal | vauthors = Hettrick GR |title=Vaccine Production in the Bitterroot Valley during World War II: How Rocky Mountain Laboratory Protected American Forces from Yellow Fever |journal=Montana The Magazine of Western History |date=Winter 2012 |volume=62 |issue=4 |pages=56–57 |jstor=24414669 }}</ref> Since 1971, screening technology for HBV has been available and is routinely used in situations where HBV contamination is possible including vaccine preparation.<ref>{{Cite web |title=Protection Against Viral Hepatitis Recommendations of the Immunization Practices Advisory Committee (ACIP) |url=https://www.cdc.gov/mmwr/preview/mmwrhtml/00041917.htm |access-date=28 April 2022 |website=www.cdc.gov}}</ref>
There is a small risk of more severe yellow fever-like disease associated with the vaccine. This reaction, called YEL-AVD,<ref name="pmid18419548">{{cite journal |author=Bae HG, Domingo C, Tenorio A, ''et al.'' |title=Immune response during adverse events after 17D-derived yellow fever vaccination in Europe |journal=J. Infect. Dis. |volume=197 |issue=11 |pages=1577–84 |year=2008 |month=June |pmid=18419548 |doi=10.1086/587844?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub%3dncbi.nlm.nih.gov}}</ref> causes a fairly severe disease closely resembling yellow fever caused by [[virulent]] strains of the virus. The risk factor/s for YEL-AVD are not known, although it has been suggested that it may be genetic. The 2`-5` [[oligoadenylate synthetase]] (OAS) component of the [[innate immune response]] has been shown to be particularly important in protection from Flavivirus infection. In at least one case of YEL-AVD, the patient was found to have an allelic mutation in a [[single nucleotide polymorphism]] (SNP) of the OAS gene.


Also in the 1930s, a French team developed the French neurotropic vaccine (FNV), which was extracted from [[mouse brain]] tissue.<ref>{{cite journal | vauthors = Beck AS, Wood TG, Widen SG, Thompson JK, Barrett AD | title = Analysis By Deep Sequencing of Discontinued Neurotropic Yellow Fever Vaccine Strains | journal = Scientific Reports | volume = 8 | issue = 1 | pages = 13408 | date = September 2018 | pmid = 30194325 | doi = 10.1038/s41598-018-31085-2 | pmc = 6128858 | bibcode = 2018NatSR...813408B }}</ref> Since this vaccine was associated with a higher incidence of [[encephalitis]], FNV was not recommended after 1961. Vaccine 17D is still in use, and more than 400 million doses have been distributed. Little research has been done to develop new vaccines. Newer vaccines, based on [[vero cell]]s, are in development (as of 2018).<ref name=Toll2009>{{cite journal | vauthors = Tolle MA | title = Mosquito-borne diseases | journal = Current Problems in Pediatric and Adolescent Health Care | volume = 39 | issue = 4 | pages = 97–140 | date = April 2009 | pmid = 19327647 | doi = 10.1016/j.cppeds.2009.01.001 }}</ref><ref name=NIH-2016>{{cite press release | url = https://www.nih.gov/news-events/nih-launches-early-stage-yellow-fever-vaccine-trial | title = NIH launches early-stage yellow fever vaccine trial | date = 27 July 2016 | author = National Institutes of Health | publisher = [[United States Department of Health and Human Services]] | access-date = 14 July 2019| author-link = National Institutes of Health }}</ref><ref name=ClinicalTrials-2018>{{citation | url = https://clinicaltrials.gov/ct2/show/NCT02743455 | title = A Phase I Trial to Evaluate the Safety, Reactogenicity, and Immunogenicity of MVA-BN Yellow Fever Vaccine With and Without Montanide ISA-720 Adjuvant in 18-45 Year Old Healthy Volunteers (NCT number: NCT02743455) | date = 1 June 2018 | author = [[National Institute of Allergy and Infectious Diseases]] (NIAID) | publisher = [[United States National Library of Medicine]] | access-date = 14 July 2019}}.</ref>
The Canadian Medical Association published a 2001 CMAJ article entitled "Yellow fever vaccination: be sure the patient needs it".<ref>{{cite journal|last=Weir|first=E|title=Yellow fever vaccination: be sure the patient needs it.|journal=CMAJ : Canadian Medical Association journal = journal de l'Association medicale canadienne|date=2001-10-02|year=2001|month=October|volume=165|issue=7|pages=941|pmid=11599337}}</ref> The article begins by stating that of the 7 people who developed system failure within 2 to 5 days of the vaccine in 1996-2001, 6 died "including 2 who were vaccinated even though they were planning to travel to countries where yellow fever has never been reported." The article cites that "3 demonstrated histopatholic changes consistent with wild yellow fever virus." The author recommends vaccination for only non-contraindicated travelers (see the articles list) and those travellers going where yellow fever activity is reported or in the endemic zone which can be found mapped at the CDC website cited below. In addition, the 2010 online edition of the Center for Disease Control Traveler's Health Yellow Book that between 1970-2002 only "nine cases of yellow fever were reported in unvaccinated travelers from the United States and Europe who travelled" to West Africa and South America, and 8 of the 9 died. However, it goes on to state that of travelers "only one ''documented'' case of yellow fever has occurred, which was in a vaccinated traveler from Spain...in 1988".<ref>{{cite web|title=Yellow Fever|url=http://wwwnc.cdc.gov/travel/yellowbook/2010/chapter-2/yellow-fever.htm|work=Yellow Book|publisher=Center for Disease Control (Canada)|author=Mark Gershman, Betsy Schroeder, and J. Erin Staples|accessdate=1 July 2011}}</ref>


==Manufacture and global supply==
==Candidates for vaccination==
People most at risk of contracting the virus should be vaccinated. Woodcutters working in tropical areas should be particularly targeted for vaccination. [[Insecticide]]s, protective clothing, and screening of houses are helpful, but not always sufficient for mosquito control; people should always use an insecticide spray while in certain areas. In affected areas, [[mosquito control]] methods have proven effective in decreasing the number of cases.<ref>{{cite web|url=http://www.epa.gov/pesticides/health/mosquitoes/mosquitojoint.htm#programs |title= Joint Statement on Mosquito Control in the United States from the U.S. Environmental Protection Agency (EPA) and the U.S. Centers for Disease Control and Prevention (CDC) |accessdate= June 25, 2006 |date= 2000-05-03|format=PDF |publisher=Environmental Protection Agency }}</ref>


Increases in cases of yellow fever in endemic areas of Africa and South America in the 1980s were addressed by the WHO Yellow Fever Initiative launched in the mid-2000s.<ref>{{cite web |title=The Yellow fever initiative: an introduction |url=https://www.who.int/csr/disease/yellowfev/introduction/en/ |publisher=[[World Health Organization]] (WHO) |access-date=23 April 2016 |url-status=dead |archive-url=https://web.archive.org/web/20160510170639/http://www.who.int/csr/disease/yellowfev/introduction/en/ |archive-date=10 May 2016 }}</ref> The initiative was supported by the [[GAVI Alliance|Gavi Alliance]], a collaboration of the [[WHO]], [[UNICEF]], vaccine manufacturers, and private philanthropists such as the [[Bill & Melinda Gates Foundation]].<ref>{{Cite web |title=COVAX Facility |url=https://www.gavi.org/covax-facility |access-date=28 April 2022 |website=www.gavi.org |language=en}}</ref> Gavi-supported vaccination campaigns since 2011 have covered 88 million people in 14 countries considered at "high-risk" of a yellow fever outbreak (Angola was considered "medium risk"). As of 2013, there were four WHO-qualified manufacturers: Bio-Manguinhos in Brazil (with the [[Oswaldo Cruz Foundation]]), [[Institute Pasteur]] in Dakar, Senegal, the Federal State Unitary Enterprise of Chumakov Institute in Russia, and [[Sanofi Pasteur]], the French pharmaceutical company.<ref name="shortage">{{cite web |date=4 April 2016 |title=Angolan yellow fever outbreak highlights dangerous vaccine shortage |url=https://www.science.org/content/article/angolan-yellow-fever-outbreak-highlights-dangerous-vaccine-shortage |url-status=live |archive-url=https://web.archive.org/web/20160425124828/http://www.sciencemag.org/news/2016/04/angolan-yellow-fever-outbreak-highlights-dangerous-vaccine-shortage |archive-date=25 April 2016 |access-date=24 April 2016 |website=[[Science (journal)|Science]] |vauthors=Kupferschmidt K}}</ref><ref>{{cite web|title=Yellow Fever Vaccine: Current Outlook|url=http://www.unicef.org/supply/files/YFV_Supply_Status_Update.pdf|publisher=Unicef|access-date=23 April 2016|url-status=live|archive-url=https://web.archive.org/web/20160304194853/http://www.unicef.org/supply/files/YFV_Supply_Status_Update.pdf|archive-date=4 March 2016}}</ref> Two other manufacturers supply domestic markets: Wuhan Institute of Biological Products in China and [[Sanofi Pasteur]] in the United States.<ref name="nejm.org">{{cite journal |vauthors=Barrett AD |date=July 2016 |title=Yellow Fever in Angola and Beyond--The Problem of Vaccine Supply and Demand |journal=The New England Journal of Medicine |volume=375 |issue=4 |pages=301–303 |doi=10.1056/NEJMp1606997 |pmid=27276108 |doi-access=free |s2cid=7983551}}</ref>
==References==

{{reflist|2}}
Demand for yellow fever vaccine for preventive campaigns has increased from about five million doses per year to a projected 62 million per year by 2014.<ref>{{cite web|title=Fever Vaccine: Current Outlook November 2013|url=http://www.unicef.org/supply/files/YFV_Supply_Status_Update.pdf|publisher=UNICEF|access-date=23 April 2016|url-status=live|archive-url=https://web.archive.org/web/20160304194853/http://www.unicef.org/supply/files/YFV_Supply_Status_Update.pdf|archive-date=4 March 2016}}</ref> UNICEF reported in 2013 that supplies were insufficient. Manufacturers are producing about 35 million of the 64 million doses needed per year.<ref>{{cite web|title=Complacency Led to Resurgence of Yellow Fever|url=http://www.globalhealthnow.org/news/complacency-led-to-resurgence-of-yellow-fever|website=globalhealthnow.org|access-date=23 April 2016|url-status=dead|archive-url=https://web.archive.org/web/20160507061108/http://www.globalhealthnow.org/news/complacency-led-to-resurgence-of-yellow-fever|archive-date=7 May 2016}}</ref> Demand for the yellow fever vaccine has continued to increase due to the growing number of countries implementing yellow fever vaccination as part of their routine immunization programmes.<ref name=WHO2016>{{cite book | vauthors=((World Health Organization)) | title=Fractional dose yellow fever vaccine as a dose-sparing option for outbreak response: WHO Secretariat information paper | id=WHO/YF/SAGE/16.1 | date=July 2016 | author-link = World Health Organization | hdl=10665/246236 }}</ref>

[[2016 yellow fever epidemic in Angola|The outbreak of yellow fever in Angola and in the Democratic Republic of Congo]] in 2016 has raised concerns about whether the global supply of vaccine is adequate to meet the need during a large epidemic or [[pandemic]] of the disease.<ref>{{cite web |title=Yellow Fever Deaths Reach 250 in Angola {{!}} HealthMap |url=http://www.healthmap.org/site/diseasedaily/article/yellow-fever-deaths-reach-250-angola-42616 |url-status=dead |archive-url=https://web.archive.org/web/20160429084509/http://www.healthmap.org/site/diseasedaily/article/yellow-fever-deaths-reach-250-angola-42616 |archive-date=29 April 2016 |access-date=28 April 2016 |website=healthmap.org}}</ref> Routine childhood immunization was suspended in other African countries to ensure an adequate supply in the vaccination campaign against the outbreak in Angola.<ref name="pmid27116054">{{cite journal |vauthors=Monath TP, Woodall JP, Gubler DJ, Yuill TM, Mackenzie JS, Martins RM, Reiter P, Heymann DL |date=April 2016 |title=Yellow fever vaccine supply: a possible solution |journal=Lancet |volume=387 |issue=10028 |pages=1599–1600 |doi=10.1016/S0140-6736(16)30195-7 |pmid=27116054 |s2cid=13106004}}</ref> Emergency stockpiles of vaccine diverted to Angola, which consisted of about 10 million doses at the end of March 2016, had become exhausted,<ref name="shortage" /><ref>{{cite press release |title=Angola extends yellow fever vaccination campaign to Huambo and Benguela provinces |url=http://www.afro.who.int/en/media-centre/pressreleases/item/8528-angola-extends-yellow-fever-vaccination-campaign-to-huambo-and-benguela-provinces.html |website=[[World Health Organization]] (WHO) |access-date=24 April 2016 |url-status=live |archive-url=https://web.archive.org/web/20160423183006/http://www.afro.who.int/en/media-centre/pressreleases/item/8528-angola-extends-yellow-fever-vaccination-campaign-to-huambo-and-benguela-provinces.html |archive-date=23 April 2016}}</ref> but were being replenished by May 2016.<ref>{{cite journal |vauthors=Kupferschmidt K |date=19 May 2016 |title=Yellow fever threat is 'serious' but not an 'emergency,' WHO says |journal=Science |doi=10.1126/science.aaf5736 |issn=0036-8075}}</ref> However, in August it was reported that about one million doses of six million shipped in February had been sent to the wrong place or not kept cold enough to ensure efficacy, resulting in shortages to fight the spreading epidemic in DR Congo.<ref>{{cite news |title=UN bungles response to Africa's yellow fever outbreak |url=http://bigstory.ap.org/article/c5be7d71b0cb4c99a05940f5adfc7166/ap-investigation-1-million-vaccines-vanished-angola |url-status=live |access-date=5 August 2016 |archive-url=https://web.archive.org/web/20160806005011/http://bigstory.ap.org/article/c5be7d71b0cb4c99a05940f5adfc7166/ap-investigation-1-million-vaccines-vanished-angola |archive-date=6 August 2016}}</ref> As an emergency measure, experts suggested [[fractional dose vaccination]], using a fractional dose (1/5 or 1/10 of the usual dose) to extend existing supplies of vaccine.<ref name="fYF - WHO Addendum">{{cite journal |author-link=World Health Organization |vauthors= |date=June 2017 |title=Yellow fever vaccine: WHO position on the use of fractional doses – June 2017 |journal=Weekly Epidemiological Record |volume=92 |issue=25 |pages=345–350 |pmid=28643507 |hdl=10665/255754}}</ref><ref name="pmid27116054" /> Others have noted that switching manufacturing processes to modern [[Vaccine#Production|cell-culture technology]] might improve vaccine supply shortfalls,<ref name="nejm.org" /> as the manufacture of the current vaccine in chicken eggs is slow and laborious.<ref>{{cite web |date=26 July 2016 |title=NIH launches early-stage yellow fever vaccine trial |url=https://www.nih.gov/news-events/nih-launches-early-stage-yellow-fever-vaccine-trial |url-status=live |archive-url=https://web.archive.org/web/20160826202158/https://www.nih.gov/news-events/nih-launches-early-stage-yellow-fever-vaccine-trial |archive-date=26 August 2016 |access-date=15 August 2016}}</ref> On 17 June 2016, the WHO agreed to the use of 1/5 the usual dose as an emergency measure during the ongoing outbreak in Angola and the DR Congo.<ref name="WHO2016" /><ref>{{cite press release |title=Lower doses of yellow fever vaccine could be used in emergencies |url=https://www.who.int/mediacentre/news/statements/2016/yellow-fever-vaccine/en/ |website=[[World Health Organization]] (WHO) |access-date=19 June 2016 |url-status=live |archive-url=https://web.archive.org/web/20160618152344/http://www.who.int/mediacentre/news/statements/2016/yellow-fever-vaccine/en/ |archive-date=18 June 2016 |date=17 June 2016}}</ref> The fractional dose would not qualify for a [[Carte Jaune|yellow fever certificate of vaccination]] for travelers. Later studies found that the fractional dose was just as protective as the full dose, even 10 years after vaccination.<ref>{{Cite web |last=Soucheray |first=Stephanie |date=26 November 2018 |title=Study affirms fractional dosing with yellow fever vaccine |url=https://www.cidrap.umn.edu/news-perspective/2018/11/study-affirms-fractional-dosing-yellow-fever-vaccine |access-date=8 June 2022 |website=CIDRAP News |language=en}}</ref>

As of February 2021, UNICEF reported awarded contract prices of ranging from {{Currency|0.97|US}} to {{Currency|1.444|US}} per dose under multi-year contracts with various suppliers.<ref>{{cite web |title=Yellow Fever vaccines prices 05-02-2021 |url=https://www.unicef.org/supply/media/11451/file/Yellow-fewer-vaccine-prices-10032022.pdf |publisher=Unicef |access-date=13 December 2022}}</ref>

== Travel requirements ==
[[File:Yellow fever risk countries map.svg|thumb|400px|left|{{Legend|red|Risk countries (WHO designation)}}
{{Legend|yellow|Partial risk countries (WHO designation)}}]]
[[File:Yellow fever vaccination travel requirements map.svg|thumb|400px|Vaccination against yellow fever 10 days before entering this country/territory is required for travellers coming from...
{{Legend|#008000|All countries}}
{{Legend|#00FF00|Risk countries (including airport transfers){{refn|group=note|name=transit explanation|Also required for travellers having transited (more than 12 hours) through a risk country's airport.}}}}
{{Legend|#FFFF00|Risk countries (excluding airport transfers){{refn|group=note|name=no transit|Not required for travellers having transited through a risk country's airport.}}}}
{{Legend|#D35F5F|No requirement (risk country){{refn|group=note|name=ArBrPe|The WHO has designated (parts of) Argentina, Brazil and Peru as risk countries, but these countries do not require incoming travellers to vaccinate against yellow fever.}}}}
{{Legend|#C0C0C0|No requirement (non-risk country)}}]]
{{See also|Vaccination requirements for international travel}}
Travellers who wish to enter certain countries or territories must be vaccinated against yellow fever 10 days before crossing the border, and be able to present a vaccination record/certificate at the border checks.<ref name="WHO Travel and Health">{{Cite web |url=https://www.who.int/ith/CHAPTER_6_For_Publication.pdf |title=International Travel and Health. Chapter 6 - Vaccine-preventable diseases and vaccines (2019 update) |work=World Health Organization |publisher=United Nations |date=2020 |access-date=29 November 2020}}</ref>{{rp|45}} In most cases, this travel requirement depends on whether the country they are travelling from has been designated by the World Health Organization as being a 'country with risk of yellow fever transmission'.<ref>{{Cite web |title=Countries with risk of yellow fever transmission and countries requiring yellow fever vaccination (May 2021) |url=https://www.who.int/publications/m/item/countries-with-risk-of-yellow-fever-transmission-and-countries-requiring-yellow-fever-vaccination-(may-2021) |access-date=28 April 2022 |website=www.who.int |language=en}}</ref> In a few countries, it does not matter which country the traveller comes from: everyone who wants to enter these countries must be vaccinated against yellow fever.<ref>{{Cite web |title=Nigeria - Traveler view {{!}} Travelers' Health {{!}} CDC |url=https://wwwnc.cdc.gov/travel/destinations/traveler/none/nigeria |access-date=28 April 2022 |website=wwwnc.cdc.gov}}</ref> There are exemptions for newborn children; in most cases, any child who is at least 9 months or 1 year old needs to be vaccinated.<ref name="WHO country list">{{Cite web |url=https://www.who.int/publications/m/item/countries-with-risk-of-yellow-fever-transmission-and-countries-requiring-yellow-fever-vaccination-(july-2019) |title=Countries with risk of yellow fever transmission and countries requiring yellow fever vaccination (July 2019) |work=World Health Organization |publisher=United Nations |date=4 July 2019 |access-date=29 November 2020}}</ref>

{| class="wikitable sortable" style="text-align:left;" width=1000 align="left"
! colspan="4" align="left" | Yellow fever vaccination requirements for international travel (July 2019)<ref name="WHO country list"/>
|-
! align="left" | Country or territory
! Status
! Vaccination required for travellers coming from
! Traveller age
|-
| {{flag|Albania}}
| {{CMain|No risk}}
| {{depends|Risk countries}}
| 1 year or older
|-
| {{flag|Algeria}}
| {{CMain|No risk}}
| {{depends|Risk countries{{refn|group=note|name=12+ hour transit|Also required for travellers having transited more than 12 hours through a risk country's airport.}}}}
| 1 year or older
|-
| {{flag|Angola}}
| {{CRecurring|Risk country}}
| {{yes|All countries}}
| 9 months or older
|-
| {{flag|Antigua and Barbuda}}
| {{CMain|No risk}}
| {{depends|Risk countries}}
| 1 year or older
|-
| {{flag|Argentina}}
| {{partial|Risk provinces:<br/>[[Misiones Province|Misiones]], [[Corrientes Province|Corrientes]]}}
| {{No}}{{refn|group=note|name=ArBrPe}}
| –
|-
| {{flag|Aruba}}
| {{CMain|No risk}}
| {{depends|Risk countries{{refn|group=note|name=12+ hour transit}}}}
| 9 months or older
|-
| {{flag|Australia}}
| {{CMain|No risk}}
| {{depends|Risk countries{{refn|group=note|name=12+ hour transit}}}}
| 1 year or older
|-
| {{flag|Bahamas}}
| {{CMain|No risk}}
| {{depends|Risk countries{{refn|group=note|name=12+ hour transit}}}}
| 1 year or older
|-
| {{flag|Bahrain}}
| {{CMain|No risk}}
| {{depends|Risk countries{{refn|group=note|name=12+ hour transit}}}}
| 9 months or older
|-
| {{flag|Bangladesh}}
| {{CMain|No risk}}
| {{depends|Risk countries{{refn|group=note|name=any transit|Also required for travellers having transited any time through a risk country's airport.}}}}
| 1 year or older
|-
| {{flag|Barbados}}
| {{CMain|No risk}}
| {{depends|Risk countries}}
| 1 year or older
|-
| {{flag|Belize}}
| {{CMain|No risk}}
| {{depends|Risk countries{{refn|group=note|name=any transit}}}}
| 1 year or older
|-
| {{flag|Benin}}
| {{CRecurring|Risk country}}
| {{depends|Risk countries{{refn|group=note|name=any transit}}}}
| 1 year or older
|-
| {{flag|Bolivia}}
| {{CRecurring|Risk country}}
| {{depends|Risk countries}}
| 1 year or older
|-
| {{flag|Bonaire}}
| {{CMain|No risk}}
| {{depends|Risk countries{{refn|group=note|name=12+ hour transit}}}}
| 9 months or older
|-
| {{flag|Botswana}}
| {{CMain|No risk}}
| {{depends|Risk countries{{refn|group=note|name=any transit}}}}
| 1 year or older
|-
| {{flag|Brazil}}
| {{CRecurring|Risk country}}
| {{No}}{{refn|group=note|name=ArBrPe}}
| –
|-
| {{flag|Brunei}}
| {{CMain|No risk}}
| {{depends|Risk countries{{refn|group=note|name=12+ hour transit}}}}
| 9 months or older
|-
| {{flag|Burkina Faso}}
| {{CRecurring|Risk country}}
| {{depends|Risk countries{{refn|group=note|name=any transit}}}}
| 9 months or older
|-
| {{flag|Burundi}}
| {{CRecurring|Risk country}}
| {{depends|Risk countries{{refn|group=note|name=any transit}}}}
| 9 months or older
|-
| {{flag|Cabo Verde}}
| {{CMain|No risk}}
| {{depends|Risk countries{{refn|group=note|name=12+ hour transit}}}}
| 1 year or older
|-
| {{flag|Cambodia}}
| {{CMain|No risk}}
| {{depends|Risk countries{{refn|group=note|name=12+ hour transit}}}}
| 1 year or older
|-
| {{flag|Cameroon}}
| {{CRecurring|Risk country}}
| {{yes|All countries}}
| 9 months or older
|-
| {{flag|Central African Republic}}
| {{CRecurring|Risk country}}
| {{yes|All countries}}
| 9 months or older
|-
| {{flag|Chad}}
| {{CRecurring|Risk country}}
| {{yes|All countries}}
| 9 months or older
|-
| {{flag|China}}
| {{CMain|No risk}}
| {{depends|Risk countries{{refn|group=note|name=any transit}}}}
| 9 months or older
|-
| {{flag|Christmas Island}}
| {{CMain|No risk}}
| {{depends|Risk countries{{refn|group=note|name=12+ hour transit}}}}
| 1 year or older
|-
| {{flag|Colombia}}
| {{CRecurring|Risk country}}
| {{depends|Risk countries{{refn|group=note|name=12+ hour transit}}}}
| 1 year or older
|-
| {{flag|Congo-Brazzaville}}
| {{CRecurring|Risk country}}
| {{yes|All countries}}
| 9 months or older
|-
| {{flag|Congo-Kinshasa}}
| {{CRecurring|Risk country}}
| {{yes|All countries}}
| 9 months or older
|-
| {{flag|Costa Rica}}
| {{CMain|No risk}}
| {{depends|Risk countries}}
| 9 months or older
|-
| {{flag|Côte d'Ivoire}}
| {{CRecurring|Risk country}}
| {{yes|All countries}}
| 9 months or older
|-
| {{flag|Cuba}}
| {{CMain|No risk}}
| {{depends|Risk countries{{refn|group=note|name=12+ hour transit}}}}
| 9 months or older
|-
| {{flag|Curaçao}}
| {{CMain|No risk}}
| {{depends|Risk countries{{refn|group=note|name=12+ hour transit}}}}
| 9 months or older
|-
| {{flag|Dominica}}
| {{CMain|No risk}}
| {{depends|Risk countries{{refn|group=note|name=12+ hour transit}}}}
| 1 year or older
|-
| {{flag|Dominican Republic}}
| {{CMain|No risk}}
| {{depends|Risk countries{{refn|group=note|name=12+ hour transit}}}}
| 1 year or older
|-
| {{flag|Ecuador}}
| {{CRecurring|Risk country}}
| {{depends|Risk countries{{refn|group=note|name=12+ hour transit}}}}
| 1 year or older
|-
| {{flag|Egypt}}
| {{CMain|No risk}}
| {{depends|Risk countries{{refn|group=note|name=12+ hour transit}}}}
| 9 months or older
|-
| {{flag|El Salvador}}
| {{CMain|No risk}}
| {{depends|Risk countries{{refn|group=note|name=12+ hour transit}}}}
| 1 year or older
|-
| {{flag|Equatorial Guinea}}
| {{CRecurring|Risk country}}
| {{depends|Risk countries}}
| 9 months or older
|-
| {{flag|Eritrea}}
| {{CMain|No risk}}
| {{depends|Risk countries{{refn|group=note|name=12+ hour transit}}}}
| 9 months or older
|-
| {{flag|Eswatini}}
| {{CMain|No risk}}
| {{depends|Risk countries{{refn|group=note|name=any transit}}}}
| 9 months or older
|-
| {{flag|Ethiopia}}
| {{CRecurring|Risk country}}
| {{depends|Risk countries{{refn|group=note|name=12+ hour transit}}}}
| 9 months or older
|-
| {{flag|Fiji}}
| {{CMain|No risk}}
| {{depends|Risk countries{{refn|group=note|name=12+ hour transit}}}}
| 1 year or older
|-
| {{flag|French Guiana}}
| {{CRecurring|Risk country}}
| {{yes|All countries}}
| 1 year or older
|-
| {{flag|French Polynesia}}
| {{CMain|No risk}}
| {{depends|Risk countries{{refn|group=note|name=12+ hour transit}}}}
| 9 months or older
|-
| {{flag|Gabon}}
| {{CRecurring|Risk country}}
| {{yes|All countries}}
| 1 year or older
|-
| {{flag|Gambia}}
| {{CRecurring|Risk country}}
| {{depends|Risk countries}}
| 9 months or older
|-
| {{flag|Ghana}}
| {{CRecurring|Risk country}}
| {{yes|All countries}}
| 9 months or older
|-
| {{flag|Grenada}}
| {{CMain|No risk}}
| {{depends|Risk countries{{refn|group=note|name=12+ hour transit}}}}
| 1 year or older
|-
| {{flag|Guadeloupe}}
| {{CMain|No risk}}
| {{depends|Risk countries{{refn|group=note|name=12+ hour transit}}}}
| 1 year or older
|-
| {{flag|Guatemala}}
| {{CMain|No risk}}
| {{depends|Risk countries{{refn|group=note|name=12+ hour transit}}}}
| 1 year or older
|-
| {{flag|Guinea}}
| {{CRecurring|Risk country}}
| {{depends|Risk countries}}
| 9 months or older
|-
| {{flag|Guinea-Bissau}}
| {{CRecurring|Risk country}}
| {{yes|All countries}}
| 1 year or older
|-
| {{flag|Guyana}}
| {{CRecurring|Risk country}}
| {{depends|Risk countries{{refn|group=note|name=any transit}}}}
| 1 year or older
|-
| {{flag|Haiti}}
| {{CMain|No risk}}
| {{depends|Risk countries}}
| 1 year or older
|-
| {{flag|Honduras}}
| {{CMain|No risk}}
| {{depends|Risk countries}}
| 1 year or older
|-
| {{flag|India}}
| {{CMain|No risk}}
| {{depends|Risk countries{{refn|group=note|name=any transit}}}}
| 9 months or older
|-
| {{flag|Indonesia}}
| {{CMain|No risk}}
| {{depends|Risk countries}}
| 9 months or older
|-
| {{flag|Iran}}
| {{CMain|No risk}}
| {{depends|Risk countries{{refn|group=note|name=12+ hour transit}}}}
| 9 months or older
|-
| {{flag|Iraq}}
| {{CMain|No risk}}
| {{depends|Risk countries{{refn|group=note|name=12+ hour transit}}}}
| 9 months or older
|-
| {{flag|Jamaica}}
| {{CMain|No risk}}
| {{depends|Risk countries{{refn|group=note|name=12+ hour transit}}}}
| 1 year or older
|-
| {{flag|Jordan}}
| {{CMain|No risk}}
| {{depends|Risk countries{{refn|group=note|name=12+ hour transit}}}}
| 1 year or older
|-
| {{flag|Kenya}}
| {{CRecurring|Risk country}}
| {{depends|Risk countries}}
| 1 year or older
|-
| {{flag|Kyrgyzstan}}
| {{CMain|No risk}}
| {{depends|Risk countries{{refn|group=note|name=12+ hour transit}}}}
| 1 year or older
|-
| {{flag|Laos}}
| {{CMain|No risk}}
| {{depends|Risk countries}}
| Unknown
|-
| {{flag|Lesotho}}
| {{CMain|No risk}}
| {{depends|Risk countries{{refn|group=note|name=12+ hour transit}}}}
| 6 months or older
|-
| {{flag|Liberia}}
| {{CRecurring|Risk country}}
| {{depends|Risk countries}}
| 9 months or older
|-
| {{flag|Libya}}
| {{CMain|No risk}}
| {{depends|Risk countries}}
| 1 year or older
|-
| {{flag|Madagascar}}
| {{CMain|No risk}}
| {{depends|Risk countries{{refn|group=note|name=12+ hour transit}}}}
| 9 months or older
|-
| {{flag|Malawi}}
| {{CMain|No risk}}
| {{depends|Risk countries{{refn|group=note|name=12+ hour transit}}}}
| 1 year or older
|-
| {{flag|Malaysia}}
| {{CMain|No risk}}
| {{depends|Risk countries{{refn|group=note|name=12+ hour transit}}}}
| 1 year or older
|-
| {{flag|Maldives}}
| {{CMain|No risk}}
| {{depends|Risk countries{{refn|group=note|name=12+ hour transit}}}}
| 9 months or older
|-
| {{flag|Mali}}
| {{CRecurring|Risk country}}
| {{yes|All countries}}
| 1 year or older
|-
| {{flag|Malta}}
| {{CMain|No risk}}
| {{depends|Risk countries{{refn|group=note|name=12+ hour transit}}}}
| 9 months or older
|-
| {{flag|Martinique}}
| {{CMain|No risk}}
| {{depends|Risk countries{{refn|group=note|name=12+ hour transit}}}}
| 1 year or older
|-
| {{flag|Mauritania}}
| {{CRecurring|Risk country}}
| {{depends|Risk countries}}
| 1 year or older
|-
| {{flag|Mayotte}}
| {{CMain|No risk}}
| {{depends|Risk countries{{refn|group=note|name=12+ hour transit}}}}
| 1 year or older
|-
| {{flag|Montserrat}}
| {{CMain|No risk}}
| {{depends|Risk countries{{refn|group=note|name=any transit}}}}
| 1 year or older
|-
| {{flag|Mozambique}}
| {{CMain|No risk}}
| {{depends|Risk countries{{refn|group=note|name=12+ hour transit}}}}
| 9 months or older
|-
| {{flag|Myanmar}}
| {{CMain|No risk}}
| {{depends|Risk countries{{refn|group=note|name=12+ hour transit}}}}
| 1 year or older
|-
| {{flag|Namibia}}
| {{CMain|No risk}}
| {{depends|Risk countries{{refn|group=note|name=12+ hour transit}}}}
| 9 months or older
|-
| {{flag|Nepal}}
| {{CMain|No risk}}
| {{depends|Risk countries{{refn|group=note|name=12+ hour transit}}}}
| 1 year or older
|-
| {{flag|New Caledonia}}
| {{CMain|No risk}}
| {{depends|Risk countries{{refn|group=note|name=12+ hour transit}}}}
| 1 year or older
|-
| {{flag|Nicaragua}}
| {{CMain|No risk}}
| {{depends|Risk countries}}
| 1 year or older
|-
| {{flag|Niger}}
| {{CRecurring|Risk country}}
| {{yes|All countries}}
| 1 year or older
|-
| {{flag|Nigeria}}
| {{CRecurring|Risk country}}
| {{yes|All countries}}
| 9 months or older
|-
| {{flag|Niue}}
| {{CMain|No risk}}
| {{depends|Risk countries}}
| 9 months or older
|-
| {{flag|North Korea}}
| {{CMain|No risk}}
| {{depends|Risk countries}}
| 1 year or older
|-
| {{flag|Oman}}
| {{CMain|No risk}}
| {{depends|Risk countries{{refn|group=note|name=12+ hour transit}}}}
| 9 months or older
|-
| {{flag|Pakistan}}
| {{CMain|No risk}}
| {{depends|Risk countries}}
| 1 year or older
|-
| {{flag|Panama}}
| {{CRecurring|Risk country}}
| {{depends|Risk countries{{refn|group=note|name=12+ hour transit}}}}
| 1 year or older
|-
| {{flag|Papua New Guinea}}
| {{CMain|No risk}}
| {{depends|Risk countries{{refn|group=note|name=any transit}}}}
| 1 year or older
|-
| {{flag|Paraguay}}
| {{CRecurring|Risk country}}
| {{depends|Risk countries}}
| 1 year or older
|-
| {{flag|Peru}}
| {{CRecurring|Risk country}}
| {{No}}{{refn|group=note|name=ArBrPe}}
| –
|-
| {{flag|Philippines}}
| {{CMain|No risk}}
| {{depends|Risk countries{{refn|group=note|name=12+ hour transit}}}}
| 1 year or older
|-
| {{flag|Pitcairn Islands}}
| {{CMain|No risk}}
| {{depends|Risk countries}}
| 1 year or older
|-
| {{flag|Rwanda}}
| {{CMain|No risk}}
| {{depends|Risk countries}}
| 1 year or older
|-
| {{flag|Saint Barthélemy}}
| {{CMain|No risk}}
| {{depends|Risk countries{{refn|group=note|name=12+ hour transit}}}}
| 1 year or older
|-
| {{flag|Saint Helena}}
| {{CMain|No risk}}
| {{depends|Risk countries}}
| 1 year or older
|-
| {{flag|Saint Kitts and Nevis}}
| {{CMain|No risk}}
| {{depends|Risk countries}}
| 1 year or older
|-
| {{flag|Saint Lucia}}
| {{CMain|No risk}}
| {{depends|Risk countries}}
| 9 months or older
|-
| {{flag|Saint Martin}}
| {{CMain|No risk}}
| {{depends|Risk countries{{refn|group=note|name=12+ hour transit}}}}
| 1 year or older
|-
| {{flag|Saint Vincent and the Grenadines}}
| {{CMain|No risk}}
| {{depends|Risk countries}}
| 1 year or older
|-
| {{flag|Samoa}}
| {{CMain|No risk}}
| {{depends|Risk countries{{refn|group=note|name=12+ hour transit}}}}
| 1 year or older
|-
| {{flag|São Tomé and Príncipe}}
| {{CMain|No risk}}
| {{depends|Risk countries{{refn|group=note|name=any transit}}}}
| 1 year or older
|-
| {{flag|Saudi Arabia}}
| {{CMain|No risk}}
| {{depends|Risk countries{{refn|group=note|name=12+ hour transit}}}}
| 1 year or older
|-
| {{flag|Senegal}}
| {{CRecurring|Risk country}}
| {{depends|Risk countries{{refn|group=note|name=any transit}}}}
| 9 months or older
|-
| {{flag|Seychelles}}
| {{CMain|No risk}}
| {{depends|Risk countries{{refn|group=note|name=12+ hour transit}}}}
| 1 year or older
|-
| {{flag|Sierra Leone}}
| {{CRecurring|Risk country}}
| {{yes|All countries}}
| Unknown
|-
| {{flag|Singapore}}
| {{CMain|No risk}}
| {{depends|Risk countries{{refn|group=note|name=12+ hour transit}}}}
| 1 year or older
|-
| {{flag|Sint Eustatius}}
| {{CMain|No risk}}
| {{depends|Risk countries}}
| 6 months or older
|-
| {{flag|Sint Maarten}}
| {{CMain|No risk}}
| {{depends|Risk countries}}
| 9 months or older
|-
| {{flag|Solomon Islands}}
| {{CMain|No risk}}
| {{depends|Risk countries}}
| 9 months or older
|-
| {{flag|Somalia}}
| {{CMain|No risk}}
| {{depends|Risk countries{{refn|group=note|name=12+ hour transit}}}}
| 9 months or older
|-
| {{flag|South Africa}}
| {{CMain|No risk}}
| {{depends|Risk countries{{refn|group=note|name=12+ hour transit}}}}
| 1 year or older
|-
| {{flag|South Sudan}}
| {{CRecurring|Risk country}}
| {{yes|All countries}}
| 9 months or older
|-
| {{flag|Sri Lanka}}
| {{CMain|No risk}}
| {{depends|Risk countries{{refn|group=note|name=12+ hour transit}}}}
| 9 months or older
|-
| {{flag|Sudan}}
| {{CRecurring|Risk country}}
| {{depends|Risk countries{{refn|group=note|name=12+ hour transit}}}}
| 1 year or older
|-
| {{flag|Suriname}}
| {{CRecurring|Risk country}}
| {{depends|Risk countries{{refn|group=note|name=12+ hour transit}}}}
| 1 year or older
|-
| {{flag|Tanzania}}
| {{CMain|No risk}}
| {{depends|Risk countries{{refn|group=note|name=12+ hour transit}}}}
| 1 year or older
|-
| {{flag|Thailand}}
| {{CMain|No risk}}
| {{depends|Risk countries{{refn|group=note|name=12+ hour transit}}}}
| 1 year or older
|-
| {{flag|Togo}}
| {{CRecurring|Risk country}}
| {{yes|All countries}}
| 9 months or older
|-
| {{flag|Trinidad and Tobago}}
| {{Partial|Risk region:<br />[[Trinidad]]}}
| {{depends|Risk countries}}
| 1 year or older
|-
| {{flag|Uganda}}
| {{CRecurring|Risk country}}
| {{yes|All countries}}
| 1 year or older
|-
| {{flag|United Arab Emirates}}
| {{CMain|No risk}}
| {{depends|Risk countries{{refn|group=note|name=12+ hour transit}}}}
| 9 months or older
|-
| {{flag|Venezuela}}
| {{CRecurring|Risk country}}
| {{depends|Risk countries{{refn|group=note|name=12+ hour transit}}}}
| 1 year or older
|-
| {{flag|Wallis and Futuna}}
| {{CMain|No risk}}
| {{depends|Risk countries{{refn|group=note|name=12+ hour transit}}}}
| 1 year or older
|-
| {{flag|Zambia}}
| {{CMain|No risk}}
| {{depends|Risk countries{{refn|group=note|name=12+ hour transit}}}}
| 1 year or older
|-
| {{flag|Zimbabwe}}
| {{CMain|No risk}}
| {{depends|Risk countries{{refn|group=note|name=12+ hour transit}}}}
| 9 months or older
|-
| colspan="4" |
{{reflist|group="note"}}
|}
{{Clear}}

== References ==
{{reflist}}

== External links ==
* {{MeshName|Yellow Fever Vaccine}}
* {{cite web | url = https://druginfo.nlm.nih.gov/drugportal/name/yellow%20fever%20vaccine | publisher = U.S. National Library of Medicine | work = Drug Information Portal | title = Yellow Fever Vaccine }}


{{Vaccines}}
{{Vaccines}}
{{Portal bar | Medicine | Viruses }}


{{DEFAULTSORT:Yellow Fever Vaccine}}
{{DEFAULTSORT:Yellow Fever Vaccine}}
[[Category:Vaccines]]
[[Category:Live vaccines]]
[[Category:Live vaccines]]
[[Category:Vaccines]]
[[Category:World Health Organization essential medicines (vaccines)]]
[[Category:Yellow fever]]
[[Category:Wikipedia medicine articles ready to translate]]
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