Multicenter study of serotype distribution of Streptococcus pneumoniae nasopharyngeal isolates from healthy children in the Russian Federation after introduction of PCV13 into the National Vaccination Calendar.

Russia introduced PCV13 in 2014. We studied the serotype composition of S. pneumoniae isolated from the nasopharynx of healthy children younger than 6 years in St. Petersburg, Smolensk, Perm, Krasnoyarsk, Khanty-Mansiysk and Khabarovsk, between 2016 and 2018. 2.4% of children had completed a 3-dose course of PCV13, while 25.6% had received 1 or 2 doses. Pneumococcal DNA detection by PCR demonstrated S. pneumoniae in 37.2% of samples with regional variation between sites (27.3 to 56.9%). There was little difference between vaccinated, partially vaccinated and un-vaccinated children. Children who had received at least 1 dose of PCV13 had lower carriage rates of vaccine serotypes than their unvaccinated peers (49.9 vs. 61.4%; p < 0.001). Children who had received at least 1 dose of PCV13 showed increased carriage rates of non-vaccine serotypes (50 vs 38.6%; P < 0.001). Especially serogroup 15AF was more prevalent among fully immunized children than among their peers (12.5 vs 2.7%; P < 0.05).

Streptococcus pneumoniae serotype distribution in children in the Russian Federation before the introduction of pneumococcal conjugate vaccines into the National Immunization Program.

WHO recommends the inclusion of PCVs in childhood vaccination programs world-wide. Many countries including the Russian Federation are currently planning the inclusion of PCVs in their National Immunization Programs and, therefore, data on the pneumococcal serotype distribution is important to estimate the potential disease impact. Here we review eight recent epidemiological studies on the pneumococcal serotype distribution from Russia. Across all studies, serotypes 6B, 14, 19F and 23F were the most prevalent. Interestingly, serotype 3 was relatively common. Serotype 19A was prevalent among AOM, CAP and nasopharyngeal isolates and among antibiotic resistant isolates in all age groups. The differences in serotype coverage between PCV10 and PCV13 were up to 26%. Based on the current data on serotype distribution, a wide use of PCVs in Russia may lead to a significant reduction of the pneumococcal disease burden.