In this study researchers from the United States determined the effect of maternal antibody on hepatitis A vaccine immunogenicity in infants.
The team administered hepatitis A vaccine to the infants of mothers negative for antibody to hepatitis A virus (anti-HAV) 2, 4, and 6 months of age.
In addition, the infants of anti-HAV–positive mothers were randomized to receive either hepatitis A vaccine (group 2) or hepatitis B vaccine (group 3).
Infants in group 3 received hepatitis A vaccine at 8 and 10 months of age.
|100% of infants in group 1, 93% in group 2, and 92% in group 3 had protective levels of antibody.|
|Journal of Pediatrics|
The researchers found that at 15 months of age, 100% of infants in group 1, 93% in group 2, and 92% in group 3 had protective levels of antibody.
However, the team identified significant differences in the geometric mean concentration (GMC) of anti-HAV between groups:
- Group 1 = 231 mIU/mL
- Group 2 = 85 mIU/mL
- Group 3 = 84 mIU/mL.
Dr William Letson and colleagues concluded, "Passively acquired maternal anti-HAV resulted in a significantly lower final antibody response."