Radiographically confirmed community-acquired pneumonia in hospitalized adults due to pneumococcal vaccine serotypes in Sweden, 2016-2018-The ECAPS study

Front Public Health. 2023 Feb 17:11:1086648. doi: 10.3389/fpubh.2023.1086648. eCollection 2023.

Abstract

Objectives: In Sweden, pneumococcal serotype distribution in adults with community-acquired pneumonia (CAP) and potential coverage of currently licensed pneumococcal conjugate vaccines (PCVs) is unknown.

Methods: During 2016-2018, patients aged ≥18 years hospitalized with radiologically confirmed (RAD+) CAP were enrolled at Skåne University Hospital in a study on the etiology of CAP in Sweden (ECAPS). Urine samples and blood cultures were collected per-protocol. Streptococcus pneumoniae (Spn) culture isolates were serotyped and urine samples tested for the pan-pneumococcal urinary antigen (PUAT) and multiplex urine antigen detection (UAD) assay, detecting 24 serotypes.

Results: Analyses included 518 participants with RAD+CAP; 67.4% were ≥65 years of age, 73.4% were either immunocompromised or had an underlying chronic medical condition. The proportion of CAP due to Spn identified by any method was 24.3% of which 9.3% was detected by UAD alone. The most frequently identified serotypes were 3 (26 cases, 5.0% of all CAP), and 8, 11A and 19A (10 cases each, 1.9%). In individuals aged 18-64 and ≥65 years, respectively, PCV20 serotypes contributed to 35 of 169 (20.7%) and 53 of 349 cases of all CAP (15.2%), and PCV13 serotypes caused 21 of 169 (12.4%) and 35 of 349 (10.0%) cases. PCV15 coverage was 23 of 169 (13.6%) and 42 of 349 (12.0%) in individuals aged 18-64 and ≥65 years, respectively. Overall, PCV20 increases the coverage of all CAP from 10.8% (PCV13) to 17.0%.

Conclusion: Compared to earlier pneumococcal vaccines, PCV20 expands the coverage of all-cause CAP. Routine diagnostic tests underestimate the proportion of CAP caused by Spn.

Keywords: Streptococcus pneumoniae; Sweden; community-acquired pneumonia (CAP); pneumococcal conjugate vaccine; pneumococcal vaccination.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Hospitals, University
  • Humans
  • Pneumococcal Vaccines*
  • Pneumonia*
  • Serogroup
  • Sweden

Substances

  • Pneumococcal Vaccines

Grants and funding

The work was supported by Pfizer and conducted as a research collaboration between Skåne University Hospital, Lund University, and Pfizer. Skåne University Hospital was the study sponsor. This study was also financially supported by the Anna and Edwin Berger Foundation (KR), Swedish Heart Lung Foundation (KR; #20180401), the Royal Physiographical Society (KH; Forssman's Foundation), the Skåne County Council's research and development foundation (KR), and Swedish Research Council (KR; #2019-01053). This study received funding from Pfizer Vaccines. The study funder had no role in data collection, but collaborated in study design, data interpretation and analysis, and writing this manuscript and decision to publish and preparation of the manuscript.