Safety and immunogenicity of an inactivated hepatitis A vaccine: effect of dose and vaccination schedule.

The safety and immunogenicity of three doses (360 ELISA units [EU], 720 EU, and 1440 EU) and four immunization schedules (0, 1, and 2; 0, 1, and 6; 0, 1, and 12; 0, 2, and 4 months) of an inactivated hepatitis A vaccine were investigated in 80 healthy adult volunteers. Adverse effects were mild and comparable to those in a control group given hepatitis B vaccine. Antibody levels presumed to be protective (> or = 20 mIU/mL) were achieved after one injection in 90% of vaccinees given 360 and 720 EU and in 100% given 1440 EU. After two injections, 100% of vaccinees seroconverted regardless of the dose of vaccine given. All vaccine schedules were highly immunogenic. The accelerated and high-dose schedule could be useful for people who need to be rapidly immunized. The 12-month schedule induced very high levels of anti-hepatitis A virus but had problems with compliance. The 0-, 2-, and 4-month schedule produced higher antibody levels than the conventional 0-, 1-, and 6-month schedule (P = .016). This suggests that the hepatitis A vaccine could be incorporated into existing pediatric vaccine schedules.

RCT Entities:   Population Interventions Outcomes