Changes in serotype distribution may hamper efficacy of pneumococcal conjugate vaccines in children

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Constructing Mutants in Serotype 1 Streptococcus pneumoniae strain 519/43
06:06

Constructing Mutants in Serotype 1 Streptococcus pneumoniae strain 519/43

Published on: September 11, 2020

B H Normark1, A Ortqvist, M Kalin

  • 1Department of Bacteriology, Swedish Institute for Infectious Disease Control, Solna. Birgitta.Henriques@smi.ki.se

Scandinavian Journal of Infectious Diseases
|January 5, 2002
PubMed

Insights

Pneumococcal bacteremia incidence increased in Sweden. Local pneumococcal conjugate vaccine (PCV) coverage is low, necessitating tailored, adaptable vaccines for effective disease control.

Area of Science:

  • Microbiology
  • Epidemiology
  • Vaccinology

Background:

  • An increasing incidence of pneumococcal bacteremia has been observed in Sweden over the past decade.
  • Pneumococcal conjugate vaccines (PCVs) are under consideration for introduction into routine childhood vaccination programs globally, including in Sweden.

Purpose of the Study:

  • To analyze the temporal distribution of pneumococcal serotypes in invasive isolates in Sweden.
  • To evaluate the potential vaccine coverage of new pneumococcal conjugate vaccines using Swedish invasive isolates.

Main Methods:

  • Collection of 1136 invasive pneumococcal isolates from Swedish microbiological laboratories across three time points: 1987, 1992, and 1997.
  • Analysis of serotype distribution over time.
  • Assessment of potential vaccine coverage rates for new conjugate vaccines against the collected isolates.

Main Results:

  • The serotype distribution of invasive pneumococcal isolates in Sweden exhibited fluctuations over the study period.
  • A notably low potential coverage rate was observed for the 7-valent pneumococcal conjugate vaccine in Sweden, contrasting with findings from other countries.
  • Significant temporal variations in serotype prevalence were identified.

Conclusions:

  • Pneumococcal conjugate vaccines must be specifically tailored to address current, local serotype patterns in Sweden.
  • The effectiveness of pneumococcal conjugate vaccines may require periodic updates to match evolving serotype distributions over time.
  • Current vaccine formulations may not provide optimal protection against the predominant pneumococcal serotypes circulating in Sweden.

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