FRIDAY, May 28 (HealthDay News) -- An adjuvanted split virion H1N1 vaccine is more immunogenic but is also associated with more reactions compared to a whole virion, non-adjuvanted vaccine in children, according to research published online May 27 in BMJ.
Claire S. Waddington, of the University of Oxford in the United Kingdom, and colleagues analyzed data from 937 children ages 6 months to 12 years. Participants were randomized to receive the split virion vaccine, which was adjuvanted with tocopherol-based oil in water (AS03B), or the non-adjuvanted whole virion vaccine. Both groups were given two doses spaced 21 days apart.
The researchers found that the adjuvanted vaccine was associated with higher seroconversion rates, particularly in the youngest children (ages 6 months to less than 3 years). It was slightly less immunogenic in older children compared to infants, decreasing 3 percent per year with age. It was also associated with more frequent systemic reactions and severe local reactions. The second dose of the adjuvanted vaccine was more reactogenic than the first.
"In this direct comparison of two commercially available novel H1N1 vaccines, AS03B adjuvanted split virion vaccine was more immunogenic and induced high seroconversion rates in young children. These data provide important information to guide immunization policy in an influenza pandemic and indicate the potential for improved immunogenicity of seasonal influenza vaccines in children," the authors conclude.
GlaxoSmithKline and Baxter donated vaccines for the study. Several co-authors disclosed various financial relationships with vaccine makers.
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