Breakthrough infection: Difference between revisions
Immcarle36 (talk | contribs) Added a section on the characteristics of different breakthrough infections Tags: nowiki added Visual edit |
Immcarle36 (talk | contribs) I have added a new lead section to the page. This lead expands on the ideas in the original lead section. I have deleted the sentence about infections being dangerous in places with herd immunity because I couldn't find a reliable source to back it. |
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A '''breakthrough infection''' is a case of illness in which a vaccinated individual becomes sick from the same illness that the vaccine is meant to prevent. Simply, they occur when [[Vaccine|vaccines]] fail to provide immunity against the [[pathogen]] they are designed to target. Breakthrough infections have been identified in individuals immunized against a variety of different diseases including [[Mumps]], [[Chickenpox|Varicella]] (Chicken Pox), and [[Influenza]]. The character of breakthrough infections is dependent on the virus itself. Often, the infection in the vaccinated individual results in milder symptoms and is of a shorter duration than if the infection was contracted naturally.<ref name=":0">{{Cite web|url=https://www.cdc.gov/chickenpox/hcp/clinical-overview.html|title=Chickenpox (Varicella)|last=|first=|date=1 July 2016|website=Center for Disease Control and Prevention|archive-url=|archive-date=|dead-url=|access-date=}}</ref> |
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A '''breakthrough infection''' is an [[infection]] caused by the live [[virus]] in a [[vaccine]] or, simply, a vaccinated individual becoming sick with the same illness that the vaccine is meant to prevent. Often, the infection in the vaccinated individual is milder than if contracted naturally. A breakthrough infection can be especially dangerous in locations where [[herd immunity]] exists. |
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Causes of breakthrough infections include improper administration or storage of vaccines, mutations in viruses and antibody blocking. For these reasons, vaccines are rarely 100% effective. The common flu vaccine is estimated to provide immunity to the flu in 58% of recipients.<ref>{{Cite journal|last=Osterholm|first=Michael T|last2=Kelley|first2=Nicholas S|last3=Sommer|first3=Alfred|last4=Belongia|first4=Edward A|title=Efficacy and effectiveness of influenza vaccines: a systematic review and meta-analysis|url=http://dx.doi.org/10.1016/S1473-3099(11)70295-X|journal=The Lancet Infectious Diseases|volume=12|issue=1|pages=36–44|doi=10.1016/s1473-3099(11)70295-x}}</ref> The [[measles]] vaccine fails to provide immunity to 2% of children that receive the vaccine.<ref>{{Cite news|url=http://www.nvic.org/vaccines-and-diseases/measles/measles-vaccine-effectiveness.aspx|title=How effective is measles vaccine - National Vaccine Information Center|newspaper=National Vaccine Information Center (NVIC)|access-date=2017-02-11|language=en}}</ref> However, if [[herd immunity]] exists, it typically prevents individuals who are ineffectively vaccinated from contracting the disease.<ref>{{Cite journal|last=Fine|first=P.|last2=Eames|first2=K.|last3=Heymann|first3=D. L.|date=2011-04-01|title="Herd Immunity": A Rough Guide|url=https://academic.oup.com/cid/article/52/7/911/299077/Herd-Immunity-A-Rough-Guide|journal=Clinical Infectious Diseases|language=en|volume=52|issue=7|pages=911–916|doi=10.1093/cid/cir007|issn=1058-4838}}</ref> Accordingly, herd immunity reduces the number of breakthrough infections in a population.<ref name=":3">{{Cite book|title=Kuby Immunology|last=Owen|first=Judith|last2=Punt|first2=Jenni|last3=Stranford|first3=Sharon|publisher=W.H. Freeman and Company|year=2013|isbn=978-14292-1919-8|edition=7th Edition|location=New York City, New York|pages=576-578|quote=|via=}}</ref> |
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There are many theories which attempt to explain the causes of breakthrough infections such as [[antibody]] interference or vaccine compromise due to mishandling. |
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=== Characteristics === |
=== Characteristics === |
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Revision as of 01:54, 24 February 2017
 | This article needs additional citations for verification. (April 2010) |
A breakthrough infection is a case of illness in which a vaccinated individual becomes sick from the same illness that the vaccine is meant to prevent. Simply, they occur when vaccines fail to provide immunity against the pathogen they are designed to target. Breakthrough infections have been identified in individuals immunized against a variety of different diseases including Mumps, Varicella (Chicken Pox), and Influenza. The character of breakthrough infections is dependent on the virus itself. Often, the infection in the vaccinated individual results in milder symptoms and is of a shorter duration than if the infection was contracted naturally.[1]
Causes of breakthrough infections include improper administration or storage of vaccines, mutations in viruses and antibody blocking. For these reasons, vaccines are rarely 100% effective. The common flu vaccine is estimated to provide immunity to the flu in 58% of recipients.[2] The measles vaccine fails to provide immunity to 2% of children that receive the vaccine.[3] However, if herd immunity exists, it typically prevents individuals who are ineffectively vaccinated from contracting the disease.[4] Accordingly, herd immunity reduces the number of breakthrough infections in a population.[5]
Characteristics
Breakthrough Varicella
The varicella vaccine is 85% effective at preventing varicella infection. However, 75% of individuals that are diagnosed with breakthrough varicella exhibit milder symptoms than individuals that are not vaccinated. These individuals with mild varicella have low fevers, fewer than 50 lesions on their skin and a maculopapular rashes. In contrast, unvaccinated individuals typically have a fever of 102, 200-500 skin lesions and macules (lesions that are not elevated) evolve to papules and vesicular lesions. Additionally, infection in unvaccinated individuals tends to last for a longer period of time than in individuals who have been infected.
The majority of cases of breakthrough varicella are attributed to the failure of an individual to uptake the varicella vaccine. Therefore, to prevent breakthrough infections, it is proposed that children receive a second dose of varicella vaccine less than a year after getting their first dose.
Breakthrough Mumps
The mumps vaccine is a component of the Measles, Mumps and Rubella vaccine (MMR). The mumps vaccine, specifically, is 88% effective at preventing mumps. Individuals with breakthrough cases of mumps have fewer serious complications from the infections as compared to individuals unvaccinated for mumps. These complications include the development of aseptic meningitis and encephalitis.
The cause of breakthrough mumps is not currently completely understood. Evolution of the virus (antigenic drift) is thought to explain the majority of breakthrough cases. Other theories suggest that memory T lymphocytes play a role in the development of breakthrough infections.
Breakthrough Hepatitis B
Breakthrough cases of Hepatitis B are primarily attributed to mutations in the Hepatitis B virus (HBV) that make HPV surface proteins unrecognizable to antibodies produced from the HBV vaccine. Viruses with such mutations are called “vaccine escape mutants”. Breakthrough infections may also be caused by delayed vaccination, immunosuppression, and maternal viral load. It is possible for an individual to have breakthrough infection of HBV but be asymptomatic.
External links
 | This immunology article is a stub. You can help Wikipedia by expanding it. |
- ^ "Chickenpox (Varicella)". Center for Disease Control and Prevention. 1 July 2016.
{{cite web}}: Cite has empty unknown parameter:|dead-url=(help) - ^ Osterholm, Michael T; Kelley, Nicholas S; Sommer, Alfred; Belongia, Edward A. "Efficacy and effectiveness of influenza vaccines: a systematic review and meta-analysis". The Lancet Infectious Diseases. 12 (1): 36–44. doi:10.1016/s1473-3099(11)70295-x.
- ^ "How effective is measles vaccine - National Vaccine Information Center". National Vaccine Information Center (NVIC). Retrieved 2017-02-11.
- ^ Fine, P.; Eames, K.; Heymann, D. L. (2011-04-01). ""Herd Immunity": A Rough Guide". Clinical Infectious Diseases. 52 (7): 911–916. doi:10.1093/cid/cir007. ISSN 1058-4838.
- ^ Owen, Judith; Punt, Jenni; Stranford, Sharon (2013). Kuby Immunology (7th Edition ed.). New York City, New York: W.H. Freeman and Company. pp. 576–578. ISBN 978-14292-1919-8.
{{cite book}}:|edition=has extra text (help)