Flu Booster Promotes Immune Response in Preterms

A fourth dose of Haemophilus influenzae type B (Hib) vaccine produces a strong immune response in preterm infants who have shown very low responses to Hib after the first immunization, new research suggests.

A fourth dose of Haemophilus influenzae type B (Hib) vaccine produces a strong immune response in preterm infants who have shown very low responses to Hib after the first immunization, new research suggests. The findings suggest that the Hib booster campaign recently implemented in the UK can be extended to all infants and that the extra dose can be given before 1 year of age, lead author Dr. M. H. Slack, from Princess Anne Hospital in Southampton, UK, and colleagues note. The researchers assessed the immune response of 96 preterm infants to a fourth dose of the Hib conjugate vaccine. All of the infants had received three doses of the vaccine, but had shown a limited response. In all cases, the booster vaccine was given before 1 year of age. The average age at booster vaccination was 7.8 months, the investigators report in the Archives of Disease in Childhood: Fetal and Neonatal Edition. After the initial series of vaccinations, the average Hib IgG titer, a measure of the immune response, was 0.17 micrograms per milliliter. After the booster dose, the average titer increased dramatically to 4.68 micrograms per milliliter. The researchers also noted that the extent of the response to the booster vaccine was directly related to the response following the initial vaccine series. (Source: Reuters Health News, Archives of Disease in Childhood: Fetal and Neonatal Edition, May 2004)