IMMUNOGENICITY OF HEPATITIS-B VACCINE IN HEALTHY VERY-LOW-BIRTH-WEIGHT INFANTS

We studied the immunogenic response to hepatitis B vaccine of infants weighing less than or equal to 1500 gm at birth. Infants were divided into two groups: those weighing less than or equal to 1000 gm (n = 22) and those weighing 1001 to 1501 gm (n = 28). When immunized early (3 days of age, n = 25), these infants had a response rate (defined as an tibody to hepatitis B surface antigen titer > 10 mIU/ml) of 68%, where as when the first vaccine was given at 1 month of age (n = 25), a 96% response rate was noted, irrespective of birth weight and weight at th e time of immunization (p < 0.02).