A 10-valent pneumococcal conjugate vaccine (PCV) is effective in reducing the number of new cases of likely-bacterial community-acquired pneumonia in infants in Latin America, according to a study published in this week’s PLOS Medicine.

Research found that the 10-valent PCV reduced the number of new CAP cases in infants by 22% compared to those who received the control vaccine.

The researchers reached these conclusions by performing a double-blind randomized controlled trial (the Clinical Otitis Media and Pneumonia Study; COMPAS) that enrolled around 23,821 infants living in urban areas of Argentina, Panama, and Colombia.

Half of the infants were randomly assigned to receive the 10-valent PCV at 2, 4, and 6 months of age and a booster dose at age 15-18 months, with the remaining half receiving a hepatitis control vaccine at the same intervals.

At the end of the study (average follow up 30 months), the number of new cases of likely-bacterial community-acquired pneumonia was 18.2% (95% CI: 4.1%, 30.3%) lower in the per-protocol analysis in those receiving the 10-valent PCV compared to those receiving the control vaccine.

The vaccine also led to a 16.1% (95% CI: -1.1%, 30.4%; one-sided p = 0.032) reduction in confirmed acute otitis media, a 67.1% (95% CI: 17.0%, 86.9%) reduction in vaccine serotype acute otitis media, a 65% (95% CI: 11.1%, 86.2%) reduction in any invasive pneumococcal disease, and a 100% (95% CI: 74.3%, 100%) reduction in vaccine serotype invasive pneumococcal disease.

Serious adverse events were reported in about one-fifth of children, with a similar number of reports in those receiving the PCV and control vaccine, and were not thought to be attributable to the PCV.