Hepatitis B vaccine
|Target disease||Hepatitis B|
|Trade names||Recombivax HB|
| (what is this?)
Hepatitis B vaccine is a vaccine developed for the prevention of hepatitis B virus infection. The vaccine contains one of the viral envelope proteins, hepatitis B surface antigen (HBsAg). It is produced by yeast cells, into which the genetic code for HBsAg has been inserted. A course of two to three (2-3) vaccine injections are given, the second injection at least one month after the first dose and the third injection being administered six months after the first dose. The first and second dose offer complete protection. The final injection (second or third depending on number of vaccines being administered) is to prolong protection against the hepatitis B virus.  Afterward an immune system antibody to HBsAg is established in the bloodstream. The antibody is known as anti-HBsAg. This antibody and immune system memory then provide immunity to hepatitis B infection. The first vaccine became available in 1981.
A range of vaccines is available in the market. Presently recombinant DNA vaccines are available, which means they are produced by inserting the gene for HBV into common baker's yeast where it is grown, harvested, and purified. HBV infection cannot occur from receiving hepatitis B vaccine. The common brands available are Recombivax HB (Merck), Engerix-B (GSK), Elovac B (Human Biologicals Institute, a division of Indian Immunologicals Limited), Genevac B (Serum Institute), Shanvac B, etc. These vaccines are given intramuscularly.
The invention 
The invention of the vaccine began with the realization (by virologist Alfred Prince, in 1968) that the Australia antigen was part of a virus that caused hepatitis B. Maurice Hilleman at Merck used three treatments (pepsin, urea and formaldehyde) of blood serum together with rigorous filtration to yield a product that could be used as a safe vaccine. Hilleman hypothesized that he could make an HBV vaccine by injecting patients with hepatitis B surface protein. In theory, this would be very safe, as these excess surface proteins lacked infectious viral DNA. The immune system, recognizing the surface proteins as foreign, would manufacture specially shaped antibodies, custom-made to bind to, and destroy, these proteins. Then, in the future, if the patient were infected with hepatitis B virus, the immune system could promptly deploy protective antibodies, destroying the viruses before they could do any harm.
Hilleman collected blood from gay men and intravenous drug users — groups known to be at risk for HBV infections. This was in the late 1970s, when HIV was yet unknown to medicine. In addition to the sought-after hepatitis B surface proteins, the blood samples likely contained HIV. Hilleman devised a multistep process to purify this blood so that only the hepatitis B surface proteins remained. Every known virus was killed by this process, and Hilleman was confident that the vaccine was safe.
The first large-scale trials for the blood-derived vaccine were performed on gay men, considered to be an at-risk group. Later, Hilleman’s vaccine was falsely blamed for igniting the AIDS epidemic. But, although the purified blood vaccine seemed questionable, it was determined to have indeed been free of HIV. The purification process had destroyed all viruses — including HIV. The vaccine was approved in 1981.
It was withdrawn from the marketplace when Pablo DT Valenzuela, Research Director of Chiron Corporation succeeded in 1986 in making the antigen in yeast and invented the first recombinant vaccine. The recombinant vaccine was developed by inserting the HBV gene that codes for the surface protein into a species of yeast called Saccharomyces cerevisiae. This allows the yeast to produce only the noninfectious surface protein, without any danger of introducing actual viral DNA into the final product. This is the vaccine still in use today.
Recommended populations 
Babies born to mothers who've had the hepatitis virus are vaccinated with hepatitis B surface antigen (HBsAg) and injected with hepatitis B immunoglobulin (HBIG).
Many countries now routinely vaccinate infants against hepatitis B. In countries with high rates of hepatitis B infection, vaccination of newborns has not only reduced the risk of infection, but has also led to marked reduction in liver cancer. This was reported in Taiwan where the implementation of a nationwide hepatitis B vaccination program in 1984 was associated with a decline in the incidence of childhood hepatocellular carcinoma.
In many areas, vaccination against hepatitis B is also required for all health-care and laboratory staff.
Response to vaccination 
Following the primary course of 3 vaccinations, a blood test may be taken after an interval of 1–4 months to establish if there has been an adequate response, which is defined as an anti-hepatitis B surface antigen (anti-Hbs) antibody level above 100 mIU/ml. Such a full response occurs in about 85-90% of individuals.
An antibody level between 10 and 100 mIU/ml is considered a poor response, and these people should receive a single booster vaccination at this time, but do not need further retesting.
People who fail to respond (anti-Hbs antibody level below 10 mIU/ml) should be tested to exclude current or past Hepatitis B infection, and given a repeat course of 3 vaccinations, followed by further retesting 1–4 months after the second course. Those who still do not respond to a second course of vaccination may respond to intradermal administration or to a high dose vaccine  or to a double dose of a combined Hepatitis A and B vaccine. Those who still fail to respond will require hepatitis B immunoglobulin (HBIG) if later exposed to the hepatitis B virus.
Poor responses are mostly associated with being over the age of 40 years, obesity and smoking, and also in alcoholics, especially if with advanced liver disease. Patients who are immunosuppressed or on renal dialysis may respond less well and require larger or more frequent doses of vaccine. At least one study suggests that hepatitis B vaccination is less effective in patients with HIV.
Duration of protection 
It is now believed that the hepatitis B vaccine provides indefinite protection. However, it was previously believed and suggested that the vaccination would only provide effective cover of between five and seven years, but subsequently it has been appreciated that long-term immunity derives from immunological memory which outlasts the loss of antibody levels and hence subsequent testing and administration of booster doses is not required in successfully vaccinated immunocompetent individuals. Hence with the passage of time and longer experience, protection has been shown for at least 25 years in those who showed an adequate initial response to the primary course of vaccinations, and UK guidelines now suggest that for initial responders who require ongoing protection, such as for healthcare workers, only a single booster is advocated at 5 years.
Several studies looked for a significant association between recombinant hepatitis B vaccine (HBV) and multiple sclerosis (MS) in adults. Most published scientific studies do not support a causal relationship between hepatitis B vaccination and demyelinating diseases such as MS. A 2004 study reported a significant increase in risk within 3 years of vaccination. Some of these studies were criticized for methodological problems. This controversy created public misgivings about HB vaccination, and hepatitis B vaccination in children remained low in several countries. A 2007 study found that the vaccination does not seem to increase the risk of a first episode of MS in childhood.
A 2009 study of the hepatitis B vaccine and associated risk of CNS inflammatory demyelination was conducted. The hepatitis B vaccine was found to be generally safe, however the Engerix B vaccine appeared to triple the risk of CNS inflammatory demyelination in infant boys. There have been numerous reports that the Hepatitis B vaccine is linked to Chronic Fatigue Syndrome, a syndrome marked by severe fatigue, brain fogs, and muscle pains among other symptoms.  The Engerix B vaccine contained Thiomersal, a mercury containing vaccine preservative that is being phased out at the urging of the Public Health Service in the US.
The World Health Organization recommends a pentavalent vaccine, combining vaccines against diphtheria, tetanus, pertussis and Haemophilus influenzae type B with the vaccine against hepatitis B. There is not yet sufficient evidence on how effective this pentavalent vaccine is in relation to the individual vaccines.
- "Hepatitis B Vaccine from Merck". Retrieved 2010-05-09.
- "Hepatitis B Vaccine". Doylestown, Pennsylvania: Hepatitis B Foundation. 2009-01-31. Retrieved 2009-10-22.
- "CDC Viral Hepatitis". Atlanta, Georgia: Centers for Disease Control and Prevention. 2009-07-24. Retrieved 2009-10-22.
- Howard, Colin; Zuckerman, Arie J. (1979). Hepatitis viruses of man. Boston: Academic Press. pp. 16–18. ISBN 0-12-782150-3.
- "World Hepatitis Day: The History of the Hepatitis B Vaccine" [Planned Parenthood Advocates of Arizona], 26 July 2012, http://blog.advocatesaz.org/2012/07/26/world-hepatitis-day-the-history-of-the-hepatitis-b-vaccine/
- Fisher, Lawrence M. (October 13, 1986). "Biotechnology Spotlight Now Shines On Chiron". New York Times.
- Mast; Margolis, H. S.; Fiore, A. E.; Brink, E. W.; Goldstein, S. T.; Wang, S. A.; Moyer, L. A.; Bell, B. P. et al. (2005). "A comprehensive immunization strategy to eliminate transmission of hepatitis B virus infection in the United States: recommendations of the Advisory Committee on Immunization Practices (ACIP) part 1: immunization of infants, children, and adolescents" (Free full text). MMWR. Recommendations and reports : Morbidity and mortality weekly report. Recommendations and reports / Centers for Disease Control 54 (RR–16): 1–31. PMID 16371945.
- Chang, M. -H.; Chen, C. -J.; Lai, M. -S.; Hsu, H. -M.; Wu, T. -C.; Kong, M. -S.; Liang, D. -C.; Shau, W. -Y. et al. (1997). "Universal Hepatitis B Vaccination in Taiwan and the Incidence of Hepatocellular Carcinoma in Children". New England Journal of Medicine 336 (26): 1855–1859. doi:10.1056/NEJM199706263362602. PMID 9197213.
- Joint Committee on Vaccination and Immunisation (2006). "Chapter 12 Immunisation of healthcare and laboratory staff -- Hepatitis B" (PDF). Immunisation Against Infectious Disease 2006 ("The Green Book") (3rd ed.). Edinburgh: Stationery Office. p. 468. ISBN 0-11-322528-8.
- Centers for Disease Control and Prevention (CDC) (2011). "Use of hepatitis B vaccination for adults with diabetes mellitus: recommendations of the Advisory Committee on Immunization Practices (ACIP).". MMWR Morb Mortal Wkly Rep 60 (50): 1709–11. PMID 22189894.
- Joint Committee on Vaccination and Immunisation (2006). "Chapter 18 Hepatitis B" (PDF). Immunisation Against Infectious Disease 2006 ("The Green Book") (3rd edition (Chapter 18 revised 10 October 2007) ed.). Edinburgh: Stationery Office. p. 468. ISBN 0-11-322528-8.
- King; Taylor, E. M.; Crow, S. D.; White, M. C.; Todd, J. R.; Poe, M. B.; Conrad, S. A.; Gelder, F. B. (1990). "Comparison of the immunogenicity of hepatitis B vaccine administered intradermally and intramuscularly". Reviews of infectious diseases 12 (6): 1035–1043. doi:10.1093/clinids/12.6.1035. PMID 2148433.
- Levitz; Cooper, B.; Regan, H. (1995). "Immunization with high-dose intradermal recombinant hepatitis B vaccine in healthcare workers who failed to respond to intramuscular vaccination". Infection control and hospital epidemiology : the official journal of the Society of Hospital Epidemiologists of America 16 (2): 88–91. doi:10.1086/647062. PMID 7759824.
- Cardell, K.; Åkerlind, B.; Sällberg, M.; Frydén, A. (2008). "Excellent Response Rate to a Double Dose of the Combined Hepatitis a and B Vaccine in Previous Nonresponders to Hepatitis B Vaccine". The Journal of Infectious Diseases 198 (3): 299–226. doi:10.1086/589722. PMID 18544037.
- Roome, A. J.; Walsh, S.; Cartter, M.; Hadler, J. (1993). "Hepatitis B vaccine responsiveness in Connecticut public safety personnel". Journal of the American Medical Association 270 (24): 2931–2934. doi:10.1001/jama.270.24.2931. PMID 8254852.
- Rosman, Md, A.; Basu, P.; Galvin, K.; Lieber, C. (1997). "Efficacy of a High and Accelerated Dose of Hepatitis B Vaccine in Alcoholic Patients a Randomized Clinical Trial". The American Journal of Medicine 103 (3): 217–222. doi:10.1016/S0002-9343(97)00132-0. PMID 9316554.
- Pasricha, N.; Datta, U.; Chawla, Y.; Singh, S.; Arora, S.; Sud, A.; Minz, R.; Saikia, B. et al. (2006). "Immune responses in patients with HIV infection after vaccination with recombinant Hepatitis B virus vaccine". BMC Infectious Diseases 6: 65. doi:10.1186/1471-2334-6-65. PMC 1525180. PMID 16571140. Cold or Flu like symptoms can develop after receiving the vaccine, but these are short lived. As with any injection, the muscle can become tender around the injection point for some time afterwards
- Krugman; Davidson, M. (1987). "Hepatitis B vaccine: prospects for duration of immunity". The Yale journal of biology and medicine 60 (4): 333–339. PMC 2590237. PMID 3660859.
- Petersen, K. M.; Bulkow, L. R.; McMahon, B. J.; Zanis, C.; Getty, M.; Peters, H.; Parkinson, A. J. (2004). "Duration of Hepatitis B Immunity in Low Risk Children Receiving Hepatitis B Vaccinations from Birth" (Free full text). The Pediatric Infectious Disease Journal 23 (7): 650–655. doi:10.1097/01.inf.0000130952.96259.fd. PMID 15247604.
- Gabbuti, A.; Romanò, L.; Blanc, P.; Meacci, F.; Amendola, A.; Mele, A.; Mazzotta, F.; Zanetti, A. R. (2007). "Long-term immunogenicity of hepatitis B vaccination in a cohort of Italian healthy adolescents". Vaccine 25 (16): 3129–3132. doi:10.1016/j.vaccine.2007.01.045. PMID 17291637.
- "Are booster immunisations needed for lifelong hepatitis B immunity?". The Lancet 355 (9203): 561–565. 2000. doi:10.1016/S0140-6736(99)07239-6. PMID 10683019.
- Van Damme P, Van Herck K (March 2007). "A review of the long-term protection after hepatitis A and B vaccination". Travel Med Infect Dis 5 (2): 79–84. doi:10.1016/j.tmaid.2006.04.004. PMID 17298912.
- FAQs about Hepatitis B Vaccine (Hep B) and Multiple Sclerosis, CDC
- Hernán; Jick, S. S.; Olek, M. J.; Jick, H. (2004). "Recombinant hepatitis B vaccine and the risk of multiple sclerosis: a prospective study". Neurology 63 (5): 838–842. doi:10.1212/01.WNL.0000138433.61870.82. PMID 15365133.
- Mikaeloff, Y.; Caridade, G.; Rossier, M.; Suissa, S.; Tardieu, M. (2007). "Hepatitis B Vaccination and the Risk of Childhood-Onset Multiple Sclerosis". Archives of Pediatrics & Adolescent Medicine 161 (12): 1176–1182. doi:10.1001/archpedi.161.12.1176. PMID 18056563.
- "Hepatitis B vaccine and the risk of CNS inflammatory demyelination in childhood". Neurology. 2009.
- Lanctot MD, Guylaine. "Association of American Physicians&Surgeons Report". Association of American Physicians&Surgeons Report. VRAN. Retrieved 11 March 2011.
- "Thiomersal in Vaccines". U.S. Food and Drug Administration. 2010-03-31.
- Bar-On ES, Goldberg E, Hellmann S, Leibovici L (2012). "Combined DTP-HBV-HIB vaccine versus separately administered DTP-HBV and HIB vaccines for primary prevention of diphtheria, tetanus, pertussis, hepatitis B and Haemophilus influenzae B (HIB)". Cochrane Database Syst Rev (4): CD005530. doi:10.1002/14651858.CD005530.pub3. PMID 22513932.