Efficacy of antigen dosage on the hepatitis B vaccine response in infants born to hepatitis B-uninfected and hepatitis B-infected mothers.

Objective To compare the safety and immunogenicity of two dosages of recombinant hepatitis B (HB) vaccine administered to infants born to HB-uninfected and HB-infected mothers. Methods A phase III, controlled, single-blinded clinical trial was conducted with 506 healthy newborns. The newborns were assigned to three groups based on maternal levels of HB surface antigen (HBsAg) and HB e antigen (HBeAg): Group A, HBsAg negative; Group B, HBsAg positive and HBeAg negative; and Group C, HBsAg positive and HBeAg positive. Three doses of 10 or 5 μg recombinant HB vaccine were randomly administered by 1:1 within 24 h after birth, at 1 month and at 6 months. Safety data and pre- and postvaccination blood samples were collected. Results A total of 326, 93, and 87 subjects were included in Groups A, B, and C, respectively. Both dosages of HB vaccine were well tolerated by all subjects. The most common injection-site adverse reactions (ARs) and systemic ARs were pain and fever. After 1 month of the third dose, the Group A infants who received the 10 μg HB vaccine achieved a higher geometric mean concentration (GMC) of HB surface antibody (anti-HBs) than those who received the 5 μg dosage. Maternal anti-HBs serostatus did not influence HB vaccine immunogenicity at either dosage. In contrast, there was no significant difference in the anti-HBs seroconversion rate, GMCs, or estimated vaccine efficacy (EVE) against perinatal transmission between Groups B and C, regardless of dosage. However, the seroconversion rate and EVE of the 5 μg HB vaccine was lower in Group C than in Group B. Conclusions Both dosages of the HB vaccine were well tolerated and elicited a good immune response in infants of Group A, regardless of the maternal anti-HBs serostatus. EVE did not significantly differ between Groups B and C. Clinicaltrails.gov identifier: NCT02152709 [ABSTRACT FROM AUTHOR]