Pneumococcal conjugate vaccines for preventing acute otitis media in children

Review question

We reviewed the evidence for the effect of vaccination against Streptococcus pneumoniae (pneumococcus, a type of bacterium) for preventing acute middle ear infections in children.

Background

Before nationwide implementation of vaccination against S pneumoniae with pneumococcal conjugate vaccines (PCVs), pneumococcus was the most frequent cause of acute middle ear infections in children. Vaccination against this bacterium with PCVs may therefore lead to fewer acute middle ear infections in children. However, ongoing monitoring of the effects of PCVs on acute middle ear infections is warranted, since recent studies report a shift in bacteria causing acute middle ear infections towards pneumococcal types not included in the vaccines and other bacteria.

Study characteristics

The evidence is current up to 11 June 2020. We included 11 trials of PCVs versus control vaccines (meningococcus type C conjugate vaccine in three trials, and hepatitis A or B vaccine in eight trials) involving a total of 60,733 children. The PCVs used in the trials contained 7 to 11 different types of pneumococcus. None of the trials used the newer PCV containing 13 different types. Most trials were funded by pharmaceutical companies. Overall, risk of bias was low. In seven trials (59,415 children), children received PCVs in early infancy, whilst four trials included 1318 children aged one year and over who were either healthy or who had previous respiratory illness.

Key results

When a licenced vaccine containing seven different types of pneumococcus (CRM197‐PCV7) was given during early infancy, the risk of experiencing acute middle ear infections increased by 5% in high‐risk infants and decreased by 6% in low‐risk infants. When administrating a licenced vaccine containing 10 types of pneumococcus together with a carrier protein from another bacterium called Haemophilus influenzae (PHiD‐CV10), the risk of experiencing acute middle ear infections decreased by 6% to 15%, however neither of these estimates reached significance.

Giving PCV7 after early infancy (children aged one year and above) and in older children with a history of respiratory illness or frequent acute middle ear infections was not associated with reductions in acute middle ear infections.

Mild local reactions (redness, swelling), fever, and pain/tenderness were common and occurred more frequently in children receiving PCV than in those receiving control vaccines. More severe local reactions (redness and swelling > 2.5 cm) and fever (> 39 °C) occurred far less frequently and did not differ between vaccine groups. Serious adverse events judged to have been related to vaccination were rare and did not differ significantly between vaccine groups.

Certainty of the evidence

We assessed the certainty of the evidence for CRM197‐PCV7 in early infancy to be moderate (further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate). We judged the certainty of the evidence for PHiD‐CV10 to be low (further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate). We judged the certainty of the evidence for PCV7 in older children with or without a history of respiratory illness to be moderate (further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate).