Effectiveness of the 2003–2004 Influenza Vaccine Among Children 6 Months to 8 Years of Age, With 1 vs 2 Doses

Abstract

Despite a suboptimal match between the influenza vaccine and predominant circulating strains, influenza vaccination provided substantial protection for fully vaccinated children and possibly some protection for partially vaccinated children <9 years of age. These findings support vaccinating targeted children even when the vaccine match is suboptimal, and they highlight the need to vaccinate previously unvaccinated children with 2 doses for optimal protection.