Anti-HBs kinetics after HBV vaccination in neonates.

BACKGROUND AND OBJECTIVES: We report the results of a study using a recombinant DNA HBV vaccine in newborns from an endemic area for HBV and compare the anti-HBs kinetics with observations in adults in order to make estimates about the need for booster vaccinations. STUDY DESIGN: One hundred and forty-eight neonates were vaccinated and followed for 62 months. Based on the presence or absence of hepatitis B surface antigen in the mother, cohorts of 'exposed' and of 'non-exposed' neonates were identified. RESULTS: A maximum concentration is normally observed after the booster vaccination followed by a rapid decline. According to Ambrosch et al. and Gesemann et al., titer calculations as a function of time, yielded 37 IU/1 and 47 IU/1 at month 60 respectively. The mean titer for the three groups of neonates investigated was at that time 74 IU/1. The prospective time intervals to arrive at an anti-HBs level of at least 10 IU/1 can be individually calculated from the individual titer after the booster vaccination. These calculated estimates show respectively: that 8.3% of the vaccinated neonates need a new booster vaccination within 14 months; that 26.7% will need a new booster within 50 months; and that only 65% need a new booster in 50 or more months. CONCLUSION: It can be concluded that anti-HBs kinetics in very young children and adults are comparable. The least expensive way of maintaining protection against HBV in neonates seems to be the determination of the individual titers after the first booster vaccination and calculation of the prospective time interval to arrive at a minimum titer of 10 IU/1 and the need for a new booster vaccination.

The association between neonatal polycythemia, hypocalcemia, and hypoglycemia.

A study about the association between neonatal polycythemia, hypoglycemia, and hypocalcemia was carried out at the Hasan Sadikin General Hospital Bandung, Indonesia, between November 1986 and August 1987. Forty-six neonates with polycythemia were enrolled in the study and 92 neonates born during the same period formed the control subjects. The control subject neonates were sampled among those with equal birth weight and gestational age compared to the polycythemia subjects. Blood glucose levels were examined more than three hours after birth and before the first feeding by using the God-PAP method and blood calcium levels at less than 24 hours of age by using calorimetric method. The cut-off point for hypoglycemia and hypocalcemia were 30 mg% and 7 mg%, respectively. The results showed that there was a significant difference for hypoglycemia (p less than 0.01) and hypocalcemia (p less than 0.05) between the exposed subjects and the control subjects.

Immunogenicity of a recombinant DNA hepatitis B vaccine in neonates.

Infants of HBsAg-positive mothers (Group I) as well as those born to women without HBV markers (Group II) were vaccinated with a 10 micrograms dose of a recombinant DNA hepatitis B vaccine within 24 hours after birth according to a 0, 1, and 2 month schedule, with a booster dose planned 12 months later. Vaccination results in 14 (Group I) and 47 (Group II) neonates showed that at two months after the third dose of vaccine, 86% (6/7) and 100% (37/37), respectively, seroconverted, with anti-HBs geometric mean titres of 80 IU/l and 266 IU/l in the respective groups. No adverse reactions to the vaccine were observed. These preliminary results indicate that the recombinant DNA hepatitis B vaccine is safe and highly immunogenic in newborns.