PNEUMOCOCCAL SEROTYPE DISTRIBUTION: RECENT DATA IN ADULT POPULATIONS AROUND THE WORLD, 2017-2019
Pneumococcal disease remains a global health problem despite availability of vaccines (pneumococcal polysaccharide (PPV23) and pneumococcal conjugate vaccines (PCV)). Non-vaccine serotypes have emerged. As part of ongoing surveillance to monitor vaccine impact and identify newly emerging serotypes, literature was reviewed.
Medline, EMBASE, and Cochrane databases were searched from February 2017 to May 2019. Serotype distribution data for adults ≥18 years were extracted and summarized.
Serotype data were available in 22 articles covering 2012 onwards with the majority from areas where PCV was part of a pediatric immunization program. Articles covered invasive pneumococcal disease (IPD) (n=14), non-IPD (n=4), carriage (n=3), and IPD and non-IPD combined (n=1). Serotypes included in PCV13, PPV23, or in no vaccine accounted for 32.8%, 42.0% and 25.3% of serotyped isolates, respectively. The most common PCV13 and PPV23 serotypes were 3, 19A & 7F and 3, 8 & 22F, respectively. The most common non-vaccine serotypes were 15A, 6C and 23A. A similar distribution was seen among adults ≥65 years. PCV13 serotypes were more prevalent in non-IPD and carriage.
After pediatric PCV adoption in various countries, several vaccine and non-vaccine serotypes remain responsible for a significant burden of disease among adults, informing the needs for future adult vaccines.