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How effective Is Hepatitis A vaccine?
Vaccine acquired immunity is only temporary and, in some cases, vaccines may also fail to provide even temporary immunity for some individuals.
A systematic review on the efficacy of the hepatitis A vaccine completed in 2003 reported the inactivated hepatitis A vaccine to be 86 percent effective at preventing hepatitis A.
The duration of immunity following hepatitis A vaccine is unknown. A 2017 published study reviewing the antibody levels of 52 hepatitis A vaccine recipients found that 88.5 percent had measurable antibody levels after 20 years. It is important to note that while protection from hepatitis A infection may be related to the presence of antibodies, the lowest levels of antibody protection is not known.
According to GlaxoSmithKline’s package insert for TWINRIX (bivalent vaccine containing both Hepatitis A and Hepatitis B vaccine), when blood antibody levels were tested in 264 healthy adults in the U.S. one month after the completion of three doses of TWINRIX vaccine, 99.6 percent of individuals developed hepatitis A antibodies and 95.1 percent developed hepatitis B antibodies. When the blood antibody levels were tested one month following completion of the accelerated dosing schedule in 194-204 healthy adults, 100 percent of people developed hepatitis A antibodies and 96.4 percent developed hepatitis B antibodies. GlaxoSmithKline reports that TWINRIX vaccine acquired antibodies for both hepatitis A and hepatitis B persist for at least 4 years.
Persons who are immunocompromised may not develop antibodies against hepatitis A following vaccination. The package inserts for Merck’s VAQTA vaccine, and GlaxoSmithKline’s HAVRIX and TWINRIX vaccines state that vaccination may not result in protective antibodies against hepatitis A. Published studies on the use of hepatitis A vaccine in HIV positive individuals determined the vaccine to be effective approximately 50 percent of the time.
IMPORTANT NOTE: NVIC encourages you to become fully informed about Hepatitis A and the Hepatitis A vaccine by reading all sections in the Table of Contents, which contain many links and resources such as the manufacturer product information inserts, and to speak with one or more trusted health care professionals before making a vaccination decision for yourself or your child. This information is for educational purposes only and is not intended as medical advice.