Infants born to immune mothers and therefore having passively-transferred maternal antibody (PMA) to hepatitis A virus (HAV) have a blunted immune response to hepatitis A vaccine. We compared the immunogenicity of hepatitis A vaccine among infants with and without PMA, vaccinated on different schedules. We found that when vaccination is begun at or after 12 months of age, there was no difference in the immune response to the vaccine between infants born to immune vs. susceptible mothers.