Comparison of safety and immunogenicity of ADW and AYW hepatitis B vaccines

The safety and immunogenicity of adw and ayw hepatitis B vaccines were compared in a double-blind randomized trial in Green Air Force recruits. One hundred and ten out of 240 eligible nonimmune recruits were randomly selected and allocated to the two vaccine treatment groups. Two 20-micrograms doses 1 month apart and a third 20-micrograms booster dose, at 6 months, were given intramuscularly. Severe local or general side effects were not observed. The frequency of mild side effects (local discomfort or pain, fever less than 37.5 degrees C, and malaise) was slightly higher than the adw than with the ayw vaccine. Antibodies developed earlier and in higher titers in adw vaccines. However, after the booster dose all ayw and all but one adw vaccines developed anti-HBs in almost similar titers. It is concluded that both vaccines are equally safe and immunogenic after administration of two doses at a 1-month interval followed by a booster dose at 6 months.