What is Which of the following is not a live vaccine: September 2011 and explain in detail?
Ans. B: Hepatitis B Hepatitis B vaccine is a killed 'inactivated' vaccine Hepatitis B vaccine 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 inseed. A course of three (3) vaccine injections are given with the second injection at least one month after the first dose and the third injection given six months after the first dose. The first vaccine became available in 1981. Presently recombinant DNA vaccines are available, which means they are produced by inseing the gene for HBV into common baker's yeast where it is grown, harvested, and purified. 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 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.