People who may be pregnant
There is no evidence of risk from vaccinating pregnant women or those who are breastfeeding with inactivated viral or bacterial vaccines. Therefore, pregnant people can take the vaccine.
People who are immunosuppressed
Individuals with immunosuppression and HIV infection can be given hepatitis A-containing vaccines, however, it may be less effective. Extra doses of the vaccine may be required to increase immunity.
One dose recommendation
In some countries, a single dose of the hepatitis A vaccine is given, either as part of the immunisation schedule, after potential exposure to the virus, or during outbreaks.
A 2012 review of studies that looked at long-term protection of a single dose of the inactivated hepatitis A vaccine found that antibodies that protect against the hepatitis A virus can persist for almost 11 years, and that these can increase with booster doses.
The impact of single-dose hepatitis A inactivated vaccine programmes has been increasingly demonstrated in diverse settings with cases of hepatitis A decreasing by 80–99% in all age groups.
Hepatitis A vaccines are also documented to work well in people who had already been exposed to the hepatitis A virus. In Israel, an outbreak of the virus in a lower socioeconomic community (lower levels of income, education, employment etc) was completely interrupted within weeks by administering a single dose of the inactivated hepatitis A vaccine to more than 90% of the children in the community.
Read the position paper from the World Health Organization for more information.