Unexplained fever in neonates may be associated with hepatitis B vaccine

Antigen dependent adverse reactions and seroconversion of a tick-borne encephalitis vaccine in children

Two randomized, double blind dose comparison studies were conducted in 595 children in Austria and Germany with an albumin-free and thiomersal-free tick-borne encephalitis (TBE) vaccine. Vaccinated subjects of an age between 6 months and 12 years randomly assigned received either the full adult dose or half the adult dose. Results from vaccinated children under 1 year of age at the time of the first vaccination (159 subjects) showed an age dependent immune response. There were significantly fewer adverse systemic events (e.g. fever reactions). In children who received only half the adult dose, while seroconversion was not significantly different (93% versus 98%) after the second vaccination, and 100% for both groups after the third vaccination. Based on these results, it is recommended to vaccinate children between the ages of 1 and 12 years with half the adult dose.

Fever in healthy asymptomatic newborns during the first days of life

OBJECTIVE

To determine the characteristics of febrile full term infants during the first days of life, and to discover the rate of serious bacterial infections among low risk neonates with systemic fever.

DESIGN

A retrospective case-control study of 122 cases and 122 controls in a single institution.

RESULTS

Weight loss, breast feeding, caesarean section delivery, and high birth weight were found to be the most significant predictors of developing fever during the first days of life. Of the 122 patients in the study group, only one had a serious bacterial infection (a positive urine culture for group B streptococcus).

CONCLUSIONS

In low risk full term infants, fever with no other symptoms during the first days of life (but after the first day) is related primarily to dehydration, breast feeding, caesarean section, and high birth weight. Infection is the least common explanation.

Safety of neonatal hepatitis B vaccine administration

OBJECTIVE

To determine whether hepatitis B vaccination of newborns increases the incidence of fever and/or suspected sepsis.

METHODS

A prospective clinical study was undertaken at the Kaiser Permanente San Francisco Medical Center involving normal full term newborns born between November 1, 1991, and April 30, 1994. During this time 3302 infants were vaccinated within 21 days of birth with hepatitis B vaccine, and 2353 were not. Clinical and demographic data were collected from Kaiser Permanente's existing clinical information systems, and laboratory data for blood and cerebrospinal fluid (CSF) cultures were obtained from the comprehensive automated regional laboratory reporting system.

RESULTS

There were no significant differences between vaccinated and unvaccinated newborns in the proportion of infants who received care for fever (0.8% vaccinated and 1.1% unvaccinated, P = 0.28), allergic reactions, seizures or other neurologic events in the first 21 days of life. Vaccinated newborns were significantly less likely to undergo microbiologic evaluation for possible sepsis. Among vaccinated newborns 4.0% had blood cultures and 1.6% had CSF cultures. Among infants who were not vaccinated 8.3% had blood cultures and 1.6% had CSF cultures (P <0.001 for both tests).

CONCLUSION

This study found no evidence that newborn hepatitis B vaccination is associated with an increase in the number of febrile episodes, sepsis evaluations or allergic or neurologic events. In addition our data did not support any increase in medical procedures attributed to receipt of hepatitis B vaccine.