Conclusions
The 2009 pandemic influenza A /H1N1 vaccine were highly immunogenic in infants aged 6-35 months, and displayed a safety and reactogenicity profile similar to the seasonal influenza vaccine.
Results
The first vaccination of 7.5 μg and 15 μg H1N1 vaccine induced seroprotective antibody titers (HI titers≥1: 40) in 42.9-57.4% of younger infants and 49.1-61.0% older infants. Immune responses after completion of the two dose schedule were comparable in both age groups with seroprotective rates of 91-98% in each vaccine and age group and GMTs of 173-263. The H1N1 vaccine elicited similar rates of local and systemic adverse reactions as the seasonal influenza vaccine. Conclusions: The 2009 pandemic influenza A /H1N1 vaccine were highly immunogenic in infants aged 6-35 months, and displayed a safety and reactogenicity profile similar to the seasonal influenza vaccine.
Trial registration
ClinicalTrial.gov identifier: NCT01047202.