Background: Acute otitis media (AOM) is one of the most common diseases in early infancy and childhood. Long term effects of recurrent episodes of otitis media, rapid emergence of drug resistant bacteria associated with AOM worldwide and huge estimated direct and indirect annual costs associated with otitis media have emphasized the need for an effective vaccination program to prevent episodes of AOM.
Objectives: The object of this review was to assess the effect of pneumococcal vaccination in preventing AOM in children up to 12 years of age.
Search strategy: We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (issue 2, 2003) which contains the Cochrane Acute Respiratory Infection Group's specialised register (30th June 2003), MEDLINE (January 1966 to June 2003), EMBASE (January 1990 to June 2003) and reference lists of all studies and review articles retrieved. We also contacted two vaccine manufacturers and first or corresponding authors of some of the included studies.
Selection criteria: Randomised controlled clinical trials of pneumococcal vaccination with prevention of AOM as outcome in children aged 12 years or younger and a follow-up of at least six months after vaccination.
Data collection and analysis: Five reviewers independently assessed trial quality and two reviewers extracted data. Two study authors were contacted.
Main results: Eight trials on 8-to 14-valent pneumococcal polysaccharide vaccine (PPV) and four trials on 7-to 9-valent pneumococcal conjugate vaccine (PCV) were included. The highest efficacy of PPV was found in children aged 24 months and older: the rate ratio was 0.779 [95% CI: 0.625-0.970]. PPV has little effect on the prevention of AOM in children without documented prior episodes of AOM and only a moderate effect in the group of children with documented AOM episodes prior to vaccination. Pooled results of the four PCV trials in infants vaccinated as early as two months of age and toddlers attending daycare and toddlers with recurrent AOM showed only a small effect on prevention of AOM (rate ratio 0.921; 95% CI: 0.894-0.950).
Reviewer's conclusions: Based on the currently available results of the effectiveness of pneumococcal vaccination for the prevention of AOM, a large scale use of pneumococcal polysaccharide and conjugate vaccination for this specific indication is not yet recommended. So far, pneumococcal conjugate vaccinations are not indicated in the management of recurrent AOM in toddlers and older children. The results of currently ongoing trials of 9- and 11-valent conjugate vaccines should provide more information as to whether pneumococcal vaccines are more effective in specific high-risk populations like infants and older children with recurrent AOM or immunodeficiency.