NEW YORK (Reuters Health) - For children 5 to 8 years old who have never received influenza vaccine, two doses of trivalent inactivated influenza vaccine are more effective than one dose, according to a new report.Scientific support for two doses of vaccine in infants and young children has been established, the report’s authors explain, but the need for two doses of vaccine for older children to develop immunity is less certain.

Dr. Kathleen M. Neuzil from the University of Washington, Seattle, and colleagues assessed the additional benefit of a second dose of influenza vaccine in 222 vaccine-naive children 5 to 8 years old.

The investigators report that the proportion of children with protective antibody responses to the three antigens of the vaccine was significantly higher after two doses than after one dose of influenza vaccine. All age groups tolerated the influenza vaccine well after both doses, the researchers note.

The authors say this study is the first to their knowledge to compare the effects of 1 versus 2 doses of modern influenza vaccine in this age group. The results, they conclude, affirm current recommendations for 2 doses of trivalent inactivated influenza vaccine in children younger than 9 years of age receiving influenza vaccine for the first time.

“The 2-dose regimen remains the best strategy to prevent influenza illness in young children,” the investigators write.

“More resources should be devoted to improving implementation of the 2-dose regimen for previously unvaccinated children less than 9 years of age.”