Immunogenicity and reactogenicity of the combined hepatitis A and B vaccine in young adults

The combination of hepatitis A virus (HAV) and hepatitis B virus (HBV) vacc inations can offer convenience, increased compliance and cost saving. We ha ve studied the immunogenicity, reactogenicity and safety of combined hepati tis A and B vaccination in young adults (16-35 years old). Eighty healthy y oung adults were divided into two random groups. One group received the com bined hepatitis A and B vaccine (HAB) in one arm while the other group was administered concomitant hepatitis A and B vaccines (HAV + HBV) in the righ t and left arms, respectively. The immunogenicity, reactogenicity and safet y were assessed after each dose in both the groups. In local symptoms, the percentage of the combined HAB group was lower than the HAV + HBV group, an d the general symptoms were noted in approximately 30% of each group withou t any significant difference. No serious adverse effects were noted. All th e subjects were seropositive for antibody to hepatitis A virus (anti-HAV) a fter one dose of vaccine, and remained seropositive after three doses in bo th groups. The seropositive rate for antibody to hepatitis B surface antige n (anti-HBs) was significantly higher (84%) in the combined HAB group than the concomitant HAV + HBV group (62%), (p < 0.05) after dose two, and all t he subjects were seropositive (100%) after the third dose. The GMTs of anti -HAV and anti-HBs were not significantly different between groups 1 and 2 ( p > 0.1) except in month 6 when the GMT of anti-HBs was higher in HAB group (p = 0.0039). The combined HAB vaccine was found to be safe, well tolerate d and had less local symptoms in young adults. The immunogenicity and react ogenicity were similar to the concomitant HAV + HBV vaccines. (C) 2000 Else vier Science Ltd. All rights reserved.