Review of long term immunogenicity and tolerability of live hepatitis A vaccine.

Hepatitis A represents one of the major public health problems worldwide including India. Vaccination is the most effective way to prevent hepatitis A infection. Two types of hepatitis A vaccines-live attenuated (H2 strain) and inactivated (killed) are available for use in clinical practice in India with former having advantage of a single-dose compared to two-dose killed vaccine. One of the important characteristic of an ideal vaccine includes its ability to provide life-long protection. In this article we reviewed the available long-term (≥10 years follow-up) published data on live attenuated hepatitis A (H2 strain) vaccine. The data from country of origin of the vaccine (China) and India establish the long-term immunogenicity, protection, and tolerability. Based on the results of several clinical trials showing long-term protection, single dose of live attenuated hepatitis vaccine can be widely used to protect high-risk population against hepatitis A virus infection and related complications.