Long-term immunity in young adults after a single dose of inactivated Hepatitis A vaccines

Vaccine. 2006 May 15;24(20):4328-32. doi: 10.1016/j.vaccine.2006.03.010. Epub 2006 Mar 20.


We evaluated in a prospective study the immune response of naïve subjects to a single dose of inactivated Hepatitis A vaccine. Ninety-seven percent of the vaccinees sero-converted 1 month after vaccination and 93% were still positive 2 years later. All of the vaccinees had a strong booster response 2 years after the single dose. Avaxim was more immunogenic than Vaqta for the primary dose (p = 0.01 for sero-positivity, p<0.001 for antibody level) but no differences were found after boosting with Avaxim. Performance of intense physical activity during the first month after a single vaccine dose was associated with lower antibody levels (p = 0.004). This study indicates that a single dose of inactivated HAV vaccine elicits protective immune memory for at least 2 years.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Adolescent
  • Adult
  • Hepatitis A Antibodies / biosynthesis*
  • Hepatitis A Vaccines / adverse effects
  • Hepatitis A Vaccines / immunology*
  • Humans
  • Vaccines, Inactivated / immunology*


  • Hepatitis A Antibodies
  • Hepatitis A Vaccines
  • Vaccines, Inactivated