Vaccine

Vaccination is the most reliable means of preventing hepatitis A. The hepatitis A vaccine is safe and effective for people over one year of age.1 2 Two brands are available, Havrix, manufactured by GlaxoSmithKline and VAQTA, manufactured by Merck & Company, which appear similarly effective.3 There is also a combination hepatitis A and B vaccine called Twinrix (GlaxoSmithKline).

The hepatitis A vaccine is typically given in two doses, the second six to twelve months after the first. At least 95% of recipients develop antibodies within four weeks after the first dose.

Protection has been shown to last at least ten years and may last as long as 30 years.4 5 The vaccine has not been associated with serious side-effects.

United Kingdom and United States guidelines recommend vaccination for at-risk individuals, including:

  • Household contacts of people with hepatitis A.
  • Sexual partners of people with hepatitis A.
  • Men who have sex with men.
  • International travellers to areas where hepatitis A infection is endemic.
  • Injecting drug users. The United States guidelines also include users of non-injection recreational drugs.
  • People with pre-existing liver disease.

The recommendation from both the British HIV Association (BHIVA) and the United States Public Health Service is that all HIV-positive people should receive the hepatitis A vaccine unless they have already had hepatitis A or are known to have antibodies to hepatitis.

Hepatitis A vaccination has been shown to be more successful in individuals with higher CD4 cell counts. Whilst over 60% of HIV-positive people with CD4 cell counts above 500 cells/mm3 developed antibodies within six months, only 13% of people with CD4 cell counts below 200 cells/mm3 had developed antibodies.6 In a similar study, 100% of 45 patients with CD4 cell counts of 300 cells/mm3 or above developed hepatitis A antibodies, in contrast to 87% of 45 with CD4 cell counts below this value.7

People with chronic hepatitis B or C should be vaccinated because they are at increased risk for fulminant hepatitis A.

Unvaccinated individuals who are exposed to hepatitis A may benefit from post-exposure prophylaxis using injected antibodies called 'human normal immunoglobulins' (HNIGs). HNIGs should be administered within two weeks of exposure and protection lasts three to six months.

References

  1. Clemens R et al. Clinical experience with an inactivated hepatitis A vaccine. J Infect Dis 171: S44-S49, 1995
  2. Innis BL et al. Protection against hepatitis A by an inactivated vaccine. JAMA 271: 1328-1334, 1994
  3. Braconier JH et al. Comparative immunogenicity and tolerance of Vaqta and Havrix. Vaccine 17: 2181-2184, 1999
  4. Van Damme P et al. Hepatitis A booster vaccination: is there a need? Lancet 362: 1065-1071, 2003
  5. van Herck K et al. Hepatitis A vaccine: indirect evidence of immune memory 12 years after the primary course. J Med Virol 72: 194-196, 2004
  6. Kemper CA et al. Safety and immunogenicity of hepatitis A vaccine in HIV-infected patients: A double-blind, randomized, placebo-controlled trial. Journal of Infectious Diseases, 187, on-line edition, 2003
  7. Wallace MR et al. Safety and immunogenicity of an inactivated hepatitis A vaccine among HIV-infected subjects. Clin Infect Dis 39: 1207-1213, 2004
This content was checked for accuracy at the time it was written. It may have been superseded by more recent developments. NAM recommends checking whether this is the most current information when making decisions that may affect your health.