The impact of vaccination on the burden of invasive pneumococcal disease from a nationwide surveillance program in Lebanon: an unexpected increase in mortality driven by non-vaccine serotypes

Expert Rev Vaccines. 2022 Dec;21(12):1905-1921. doi: 10.1080/14760584.2022.2143349. Epub 2022 Nov 17.

Abstract

Background: The impact of pneumococcal conjugate vaccines (PCVs) on the burden of invasive pneumococcal disease (IPD) and serotype distribution was examined across age groups from data collected by the Lebanese Inter-Hospital Pneumococcal Surveillance Program.

Methods: Between 2005 and 2020, 593 invasive Streptococcus pneumoniae isolates were collected from 79 hospitals throughout Lebanon. Serotypes and antimicrobial resistance (AMR) profiles were identified, and trends compared over 3 eras: PCV7, post-PCV7/ pre-PCV13, and PCV13 eras.

Results: The prevalence of PCV7 serotypes decreased significantly from 43.6% in the PCV7 era to 17.8% during the PCV13 era (p<0.001). PCV13-only serotypes remained stable in the PCV13 compared to the post-PCV7 eras, especially serotypes 1 and 3, whereas non-vaccine types (NVT) increased throughout the study period, especially 24 and 16F. The mortality rate increased substantially from 12.5% (PCV7 era) to 24.8% (PCV13 era). A significant decrease in AMR was observed across the three study eras.

Conclusion: PCVs substantially impacted IPD and AMR in vaccinated and unvaccinated populations despite an increase in mortality driven by NVT. Broadening the recommendation of vaccination to include older age-groups, using higher valency vaccines, and implementing stringent antimicrobial stewardship are likely to further impact the burden of IPD.

Keywords: AMR; Antimicrobial resistance; IPD; PCV13; PCV7; Streptococcus pneumoniae; adults; burden; children; impact; invasive pneumococcal disease; mortality; non-vaccine type; pneumococcal conjugate vaccine; serotype; surveillance; vaccine-type.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Heptavalent Pneumococcal Conjugate Vaccine
  • Humans
  • Incidence
  • Infant
  • Lebanon / epidemiology
  • Pneumococcal Infections* / epidemiology
  • Pneumococcal Infections* / prevention & control
  • Pneumococcal Vaccines
  • Serogroup
  • Streptococcus pneumoniae
  • Vaccination
  • Vaccines, Conjugate

Substances

  • Heptavalent Pneumococcal Conjugate Vaccine
  • Pneumococcal Vaccines
  • Vaccines, Conjugate