One time exposure to contaminated food can give you the debilitating illness of Hepatitis A.
Now, however, comes word from the Centers for Disease Control and Prevention in Atlanta and the Alaska Native Tribal Health Consortium in Anchorage that the antibodies against Hepatitis A keep working for up to 27 years after vaccination.

Reuters Health, reporting on a recently published article in the Journal of Infectious Diseases, says:

Lead author Dr. Laura L. Hammitt, now at the Kenya Medical Research Institute/Welcome Trust Collaboration in Kilifi, and colleagues enrolled 144 children and 128 adults who responded to a three-shot series of hepatitis A vaccine to assess the persistence of antibodies.

The adults had received a primary dose of hepatitis A vaccine, with a second vaccination given 1 month later and a third given 12 months after the first.

The children were between 3 and 6 years of age and were given three doses at various intervals over the course of a year.

Hammitt’s team collected blood samples 1 month after vaccination and again 1 to 10 years after vaccination to test for anti-hepatitis A antibodies. The researchers calculated long-term antibody persistence based on the observed rate of decline in concentrations.

“The estimated duration of antibody persistence was 21-27 years, depending on the vaccination schedule,” Hammitt and colleagues write in the Journal of Infectious Diseases.

Get more from Reuters Health here.