The 13-valent pneumococcal conjugate vaccine (PCV13) offers better protection than its previous version, PCV7, against acute otitis media caused by Streptococcus pneumoniae, according to a study in the journal The Lancet Child & Adolescent Health. PCV13 is not currently indicated to protect against acute otitis media caused by the six additional pneumococcal serotypes it contains. However, it was approved in 2010 for various indications.
Prof Michael Pichichero and his associates conducted a study to assess the effectiveness of PCV13 in preventing acute otitis media caused by the six serotypes in PCV13 that were not in PCV7.
A longitudinal observational study included healthy children aged up to 30 months who had received the full primary series of PCV13 with other recommended vaccines to participating and were followed up to age 30–36 months to identify episodes of acute otitis media, during which middle-ear fluid (MEF) by tympanocentesis was collected.MEF for the serotypes common to PCV7 and PCV13 (4, 6B, 9V, 14, 18C, 19F, and 23F) and the six additional serotypes specific to PCV13 (1, 3, 5, 6A, 7F, and 19A) was assessed.
Children who had been vaccinated with PCV7 had MEF prospectively collected at the onset of acute otitis media were enrolled as a control group and were followed up to age 30 months. The primary outcome was the effectiveness of PCV13 to prevent acute otitis media caused by pneumococci expressing the six capsular serotypes not included in PCV7 (1, 3, 5, 6A, 7F, and 19A).
A total of 239 children were included (123 [51%] boys and 116 [49%] girls; median age of 6·3 months in the PCV13 cohort, and 162 completed the study. Of 348 children (184 [53%] boys and 164 [47%] girls; 6·5 months were included in the PCV7 cohort, 248 completed follow-up. 223 MEF samples were obtained at the onset of acute otitis media from 90 children in the PCV13 cohort.
During follow-up through age 30–36 months, S. pneumoniae was isolated from 24% of middle-ear fluid samples from children with otitis media in the PCV13 group, versus 31% from the PCV7 group. Just 8% of these isolates in the PCV13 group expressed one of the six additional serotypes in PCV13, versus 52% in the PCV7 group.
The study concluded that PCV13 prevents acute otitis media caused by S pneumoniae expressing serotypes included in the vaccine.
For more reference log on to https://doi.org/10.1016/S2352-4642(18)30168-8