The Advisory Committee on Immunization Practices voted this week to recommend a simplified double-dose influenza vaccine schedule for children for the 2012-2013 influenza season.
Many children have been exposed to the predominant circulating strains and vaccine strains in the past few years, and the 2011-2012 influenza season was one of the shortest peak years since influenza surveillance began. Therefore, ACIP members said the appropriate dosage for each child would be determined by their pediatrician, who would first determine whether the child had received two or more doses of influenza vaccine since July 2010. If so, the child would only be given one dose. If the child had never received influenza vaccine or had only received one dose, the child is to be given two doses.
Lyn Finelli, DrPH, chief of the surveillance and outbreak response team in the CDC’s Influenza Division, National Center for Immunization and Respiratory Diseases, said the 2011-12 influenza season started later than usual, and the rate of influenza was half that of the previous year. No pediatric deaths were reported.
The circulating influenza strains varied across North America, with the H3N2 strain dominating in the United States, the 2009 H1N1 virus dominating in Mexico, and the influenza B strain dominating in most territories of Canada.
“Given that this is the third year of the circulation of H1N1, the second year of H3N2, and the second year of the B Victoria strain, and the fact that there was very high immunization coverage during all three seasons, that is why, we hypothesize, it was a very mild season,” Finelli said.
ACIP recommendations do not become formal until they are published in the Morbidity and Mortality Weekly Report.