Effectiveness of the 13-valent pneumococcal conjugate vaccine on invasive pneumococcal disease in greenland

Kristiana Alexandrova Nikolova*, Mikael Andersson, Hans Christian Slotved, Anders Koch

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

The 13-valent pneumococcal conjugate vaccine (PCV13) was introduced in 2010 to the childhood vaccination program in Greenland. This study aimed to estimate the effectiveness of the PCV13 on the incidence of invasive pneumococcal disease (IPD) in children and in adults in Green-land. IPD cases from the pre-PCV13 period (January 1995–September 2010) were compared with the post-PCV13 period (September 2010–October 2020). Register data were collected from laboratory records, IPD reports, the national registry on admissions, and medical files. A total of 295 IPD cases were identified in the study period. Overall IPD incidence rate (IR) declined from the pre-PCV13 period to the post-PCV13 period (IR 23.3 to 15.3 per 100,000 person years). Overall IPD incidence among children decreased significantly, whereas overall IPD incidence among the elderly increased significantly. During the post-PCV13 period, the incidence of vaccine serotype (VT) IPD decreased in all ages, while the incidence of non-vaccine serotype (NVT) IPD increased. This increase was most substantial among elderly ≥ 60 years. In conclusion, the PCV13 has reduced incidence rates of IPD in Greenland. However, the increase in NVT IPD among the elderly is noteworthy, and sup-ports continued surveillance of IPD in the population of Greenland.

Original languageEnglish
Article number1123
JournalVaccines
Volume9
Issue number10
DOIs
Publication statusPublished - Oct 2021
Externally publishedYes

Bibliographical note

Funding Information:
Funding: This research was funded by Independent Research Fund Denmark grant number 0168-0019B, the Grosserer L.F. Foghts Fond grant number 21.778, the Dagmar Marshall Fond grant number J.nr.-500020 and J.nr.-131120, the Fonden af 1870 grant number RL-WSDOCS.FID1290380, the Ville Heise Legat grant number M18-19, the Aase og Ejnar Danielsens Fond grant number 20100179, the Holms Mindelegat grant number 20064, and Rigshospitalet University Hospital grant number E-23997-01.

Funding Information:
Conflicts of Interest: Hans-Christian Slotved is involved with projects supported by Pfizer. All other authors declare no conflict of interest.

Publisher Copyright:
© 2021 by the authors. Licensee MDPI, Basel, Switzerland.

Keywords

  • Greenland
  • Herd protection
  • Inuit
  • Invasive pneumococcal disease
  • Non-vaccine serotype
  • PCV13
  • Pneumococcal conjugate vaccine
  • Pneumococcal serotypes
  • Streptococcal infection
  • Vaccine serotype

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