Randomized controlled trial of concurrent hepatitis A and B vaccination

Hepatitis A and B viruses are threats to deployed military forces. The objective of this study was to determine the feasibility of concurrent vaccination against hepatitis A and B viruses. One hundred five healthy persons, 20 to 49 years of age and without serologic markers to hepatitis A or B viruses, were randomized to receive an inactivated hepatitis A vaccine (HEP A; 25 units in 0.5 mL), recombinant hepatitis B vaccine (HEP B; 10 micrograms in 1.0 mL), or both (HEP A & B) concurrently in separate arms. Vaccines were administered intramuscularly at 0, 1, and 6 months. Sera obtained at 1, 2, 6, 7, and 12 months after the first dose were tested for quantitative antibody to hepatitis A virus (anti-HAV) and antibody to hepatitis B surface antigen. Local reactions (e.g., pain) were reported by less than half of the volunteers and were similar at the site of HEP A, whether given alone or concurrently. However, more persons complained of pain (usually mild) at the HEP B site when HEP B was given concurrently with HEP A compared with HEP B alone (43% vs. 15%, 34% vs. 9%, and 42% vs. 15% for doses 1, 2, and 3, respectively; p < 0.05 for each dose). Among persons immunized with HEP A alone or HEP A & B, the proportion with > or = 10 mIU/mL anti-HAV was 83% in both groups 1 month after dose 1 and 100% at months 2, 7, and 12. The geometric mean concentrations of anti-HAV increased from 21 mIU/mL at month 1 to 2,649 and 2,312 mIU/mL in the HEP A and HEP A & B groups, respectively, at month 7. The response to HEP B was similar whether administered alone or concurrently. Antibody responses were similar in those receiving HEP A or HEP B concurrently or alone, but more subjects reported pain (usually mild) at the HEP B site after concurrent vaccination than after HEP B alone. Further work should be conducted to approve HEP A for patients younger than 2 years of age and to develop combined HEP A and HEP B vaccines in the United States.