NEONATAL FEVER ASSOCIATED WITH HEPATITIS B VACCINE † 951

Abstract

Objective: Since January 1992 routine active Hepatitis B vaccination on the first day of life is undertaken for all infants born in Israel. We investigated whether the immunization was associated with increased infants with unexplained neonatal fever who underwent ”sepsis work up“ and received IV antibiotic treatment. Study design: We undertook a retrospective chart review of inborn full-term infants from 1991 to 1992 in whom a diagnosis of temperature regulation disorder or antibiotic injection was recorded. Two groups of infants were compared: The non-vaccinated group - infants born in 1991 who did not receive hepatitis B vaccine. The vaccinated group - infants born in 1992 who were immunized against hepatitis B during their first day of life. ”Unexplained fever“ was defined as a temperature of > 38°C in the first three days of life without sepsis, dehydration, maternal fever or respiratory distress. Results: The incidence of unexplained fever in the vaccinated group, 35 infants out of 5910 (0.6%) was significantly higher than in the non vaccinated group, 14 infants out of 5010 (0.28%) (p < 0.005); There was however no difference in the incidence of ”explicable“ fever in the two groups. The excess of unexplained neonatal fever was associated with increase in the use of intravenous antibiotic therapy and prolonged hospitalization. Conclusions: The introduction of routine Hepatitis B immunization in newborn infants appears to be associated with an excess of infants with unexplained neonatal fever and consequently with increased length of hospitalization and intravenous antibiotic therapy. In view of the low carrier rate of hepatitis B in Israel, we suggest that in the low risk subjects the first Hepatitis B vaccine be deferred to a later age, and combined with the other immunizations given at the Maternal and Infant Welfare Centers. High risk mothers should be evaluated prenatally and infants of Hepatitis B carriers should be vaccinated soon after birth as is currently recommended.