REVIEW QUESTION

Are pneumococcal conjugate vaccines (PVCs) effective in preventing acute otitis media (AOM) in children?

TYPE OF REVIEW

A systematic review of 11 randomized controlled trials (RCTs), with a total of 60,733 children.

RELEVANCE FOR NURSING

AOM is a common childhood ailment and is most often caused by infection with Streptococcus pneumoniae, nontypeable Haemophilus influenzae, or Moraxella catarrhalis, which are present in the nasopharynx; about 40% to 50% of these organisms have variants that are resistant to antibiotics. Although AOM can resolve without antibiotic treatment in 80% of children, complications such as acute mastoiditis or meningitis are more likely in untreated patients.

Pneumococcal vaccines were developed to protect against S. pneumoniae infections, such as pneumonia, septicemia, and meningitis, and are recommended in global childhood immunization schedules. S. pneumoniae has several subspecies (known as serotypes) that can be grouped together because of similarities in surface antigens; before the development of vaccines, six to 11 serotypes accounted for most pneumococcal infections. PCVs are effective in young children when offered in repeat doses and a variety have been developed over time to tackle between seven and 13 of the most common disease-causing serotypes. However, studies have not been conducted of the effectiveness of PCVs specifically to treat AOM in young children.

CHARACTERISTICS OF THE EVIDENCE

This review included RCTs in which PCVs (active against any number of S. pneumoniae serotypes) were compared with a control, either another vaccine or a placebo. Children younger than 12 years of age who were vaccinated against AOM were followed-up for a minimum of six months. The primary outcomes were frequency of AOM of any etiology and any vaccine-related adverse effects.

Eleven RCTs were included in this review, for a total of 60,733 children. Seven trials included children in early infancy, and four included children one year of age and older. The PCVs used in the trials contained seven to 11 different types of pneumococcus.

When given in early infancy, CRM197-PCV7 (a 7-valent PCV with CRM197 as the carrier protein, active against seven serotypes of S. pneumoniae) increased the risk of experiencing AOM by 5% in high-risk infants (moderate-quality evidence) and decreased this risk by 6% in low-risk infants (high-quality evidence). PHiD-CV10, a 10-valent PCV with a carrier protein from H. influenzae, decreased the risk of experiencing AOM by 6% to 15% in healthy infants (moderate-quality evidence). Giving CRM197-PCV7 to older children and to those at higher risk because of respiratory illness or previous ear infections was not associated with decreases in AOM (high-quality evidence).

In the nine trials that reported adverse effects (high-quality evidence), there were no fatalities and very few serious adverse events in any study group. Mild local reactions and fever were common but occurred more frequently in the PCV groups than in the control groups.

BEST PRACTICE RECOMMENDATIONS

The evidence is clear that, in infants, use of the CRM197-PCV7 and PHiD-CV10 vaccines led to a greater reduction in risk of AOM caused by S. pneumoniae. However, the effect of PCVs on AOM of any etiology is uncertain, and there is no evidence of an effect in higher-risk infants and children or in low-risk children. PCVs were associated with mild local and systemic reactions. There was limited evidence that PCVs given during infancy may decrease the likelihood of further AOM episodes.

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