Simultaneous administration of hepatitis B and yellow fever vaccines.

In most developing countries, hepatitis B prevention is carried out early in life. In these countries, mobile immunization teams have a limited number of sessions to devote to each rural community; simultaneous administration of multiple antigens is thus normal practice. We compared the immune responses of Senegalese children to the separate or simultaneous injections of yellow fever and hepatitis B vaccines. Injections were given at the time of booster injection for hepatitis B vaccine. Yellow fever antibodies were detected in similar proportions in infants immunized with either yellow fever vaccine alone or yellow fever and hepatitis B vaccines simultaneously. However, a lower proportion of high yellow fever antibody levels were observed when the two vaccines were injected simultaneously. No reduction in the anamnestic response of antibodies against the surface antigen of hepatitis B virus (anti-HBs) was observed when yellow fever vaccine was injected at the same time as the booster dose of hepatitis B vaccine. Since no untoward reactions were noted, it is concluded that hepatitis B and yellow fever vaccines can be administered at the same time.