Effect of conjugate pneumococcal vaccine followed by polysaccharide pneumococcal vaccine on recurrent acute otitis media: a randomised study.

BACKGROUND: Pneumococcal conjugate vaccine prevents recurrent acute otitis media (AOM) in infants immunised at 2, 4, 6, and 12-15 months of age. We aimed to find out whether this vaccine also prevents AOM in older children who have had previous episodes of AOM. METHODS: In this double-blind, randomised study, we enrolled 383 patients aged 1-7 years who had had two or more episodes of AOM in the year before entry. Randomisation was stratified in four groups according to age (12-24 months vs 25-84 months) and the number of previous AOM episodes (two or three episodes vs four or more episodes). Children received either 7-valent pneumococcal conjugate vaccine followed by 23-valent pneumococcal polysaccharide vaccine, or hepatitis A or B vaccines. They were followed up for 18 months for recurrence of AOM. We also cultured samples of middle-ear fluid and nasopharyngeal swabs to assess association of pneumococcal serotypes with AOM after vaccination. FINDINGS: We noted no reduction of AOM episodes in the pneumococcal vaccine group compared with controls (intention-to-treat analysis: rate ratio 1.25, 95% CI 0.99-1.57). Although nasopharyngeal carriage of pneumococci of serotypes included in the conjugate-vaccine was greatly reduced after pneumococcal vaccinations, immediate and complete replacement by non-vaccine pneumococcal serotypes took place. INTERPRETATION: These data do not lend support to the use of pneumococcal conjugate vaccine to prevent otitis media in previously unvaccinated toddlers and children with a history of recurrent AOM.