Emerging non-13-valent pneumococcal conjugate vaccine (PCV13) serotypes causing adult invasive pneumococcal disease in the late-PCV13 period in Spain

Clin Microbiol Infect. 2020 Jun;26(6):753-759. doi: 10.1016/j.cmi.2019.10.034. Epub 2019 Nov 19.

Abstract

Objective: An early reduction of adult invasive pneumococcal disease (IPD) was observed after the 13-valent pneumococcal conjugate vaccine (PCV13) introduction for children in Spain. We analysed the epidemiology of adult IPD in the late-PCV13 period.

Methods: This was a prospective multicentre study of adult IPD involving six hospitals. Strains were serotyped, genotyped and studied for antimicrobial susceptibility. The late-PCV13 period was compared with the pre- and early-PCV13 periods.

Results: A total of 2197 episodes were collected-949 in 2008-2009, 609 in 2012-2013 and 639 in 2015-2016. The initial decrease of IPD observed (from 12.3/100 000 to 8.1/100 000; 2008-2009 versus 2012-2013) plateaued in 2015-2016 (8.3/100 000). IPD due to PCV13 serotypes decreased (from 7.7 to 3.5 to 2.3/100 000; p < 0.05), whereas IPD caused by non-PCV13 serotypes increased (from 4.5 to 4.6 to 6.0/100 000; p < 0.05). The most frequent serotypes in the late-PCV13 period were: 8 (15.1%), 3 (10.5%), 12F (7.9%) and 9N (5.4%). These serotypes were related to major genotypes: CC53 (59.8%) and CC404 (30.4%) for serotype 8, CC180 (64.1%) and CC260 (28.1%) for serotype 3, CC989 (91.7%) for serotype 12F and CC67 (84.8%) for serotype 9N. Penicillin-non-susceptibility (21.2%) was associated with serotypes 11A (CC156), 14 (CC156) and 19A (CC320), and macrolide-resistance was related to serotypes 24F and 19A. Rates of pneumococcal meningitis remained stable throughout the periods (ranges 0.9, 0.8 and 1.0/100 000).

Conclusions: The initial decrease of adult IPD observed after PCV13 introduction for children has been balanced by the rise of non-PCV13 serotypes. The spread of antibiotic-resistant lineages related to non-PCV13 serotypes (11A and 24F) could be a threat for the treatment of serious pneumococcal diseases.

Keywords: 13-valent pneumococcal conjugate vaccine; Invasive pneumococcal disease; Meningitis; Streptococcus pneumoniae; Vaccines.

Publication types

  • Multicenter Study

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Anti-Bacterial Agents / pharmacology
  • Bacterial Typing Techniques
  • Genotype
  • Hospitals / statistics & numerical data
  • Humans
  • Middle Aged
  • Pneumococcal Infections / epidemiology*
  • Pneumococcal Vaccines
  • Prospective Studies
  • Serogroup
  • Serotyping
  • Spain / epidemiology
  • Streptococcus pneumoniae / classification*
  • Streptococcus pneumoniae / drug effects
  • Young Adult

Substances

  • 13-valent pneumococcal vaccine
  • Anti-Bacterial Agents
  • Pneumococcal Vaccines