Re-emergence of invasive pneumococcal disease (IPD) and increase of serotype 23B after easing of COVID-19 measures, Switzerland, 2021

ABSTRACT

Incidence of invasive pneumococcal disease (IPD) has been low during the peak of the COVID-19 pandemic. In this study, we found that the IPD numbers again increased in Switzerland during the first six months of 2021 and that this coincides with the loosening of COVID-19 measures. Vaccine pneumococcal serotypes have continued to decrease and non-vaccine type serotype 23B has emerged (8% of the isolates in 2021). Worryingly, serotype 23B is associated with reduced susceptibility to penicillin.

KEYWORDS:

• Streptococcus pneumoniae
• surveillance
• COVID-19 restrictions
• non-susceptibility to penicillin
• pneumococcal conjugate vaccine (PCV)

Acknowledgments

The authors acknowledge Tania Villeneuve and Mirjam Mäusezahl-Feuz at the Federal Office of Public Health (FOPH) for their support of the IPD surveillance in Switzerland. The authors also thank Gabi Reichen and Livia Maire for their excellent technical assistance in the NZPn.

Disclosure statement

M.H. received an educational grant from Pfizer AG. However, the sponsor had no role in the data analysis and content of the manuscript. MH served on an advisory board for MSD, for which reimbursement was paid to his institution.

Additional information

Funding

The Swiss National Reference Centre for Pneumococci (NZPn) is co-funded by the Federal Office of Public health (FOPH) and the Institute for infectious Diseases, University of Bern.