Klinische ineffectiviteit van gecombineerde vaccinatie met 7-valent pneumokokkenconjugaatvaccin en 23-valent pneumokokkenpolysacharidevaccin bij kinderen met recidiverende acute otitis media; een gerandomiseerd dubbelblind onderzoek

Objective. To determine the effectiveness of a combined vaccination with 7-valent pneumococcal conjugate vaccine followed by 23-valent pneumococcal polysaccharide vaccine in children with recurrent acute otitis media (AOM). Design. Prospective, double-blind, randomised study. Method. A total of 383 patients aged 1-6 years with two or more episodes of AOM in the year prior to study entry were included. Randomisation was stratified in 4 groups according to age (12-24 months versus 25-83 months) and the number of previous AOM episodes per year (2-3 versus 4 or more). Children from the intervention group received either 7-valent pneumococcal conjugate vaccine followed by 23-valent pneumococcal polysaccharide vaccine and the control group was vaccinated with hepatitis-A or -B vaccines. All recurrences of AOM were established during an 18-month follow-up period. Secondary outcomes were nasopharyngeal pneumococcal carriage and pneumococci as pathogens of recurrent AOM episodes. Results. No reduction of AOM episodes was observed in the pneumococcal vaccine group compared to the control group (intention to treat analysis: relative risk: 1. 25; 95%-CI: 0.99-1.57). In the nasopharynx a shift from conjugate vaccine type pneumococci to non-vaccine types was observed. Conclusion. Combined 7-valent pneumococcal conjugate and 23-valent polysaccharide vaccination does not prevent AOM in children aged over i year who had already experienced recurrent episodes of AOM.