Accurate estimates of the burden of vaccine-preventable community-acquired pneumonia (CAP) hospitalisations both overall and due to the most frequent and vaccine-preventable pathogens are needed to inform the use of respiratory vaccines in adults.

This was a prospective, population-based CAP surveillance study at three hospitals in Germany. All patients admitted with clinically suspected CAP were tested for Streptococcus pneumoniae using urine antigen tests and for respiratory syncytial virus (RSV), influenza virus and SARS-CoV-2 using multiplex PCR from nasopharyngeal swabs. Incidence rate calculations for all-cause CAP were based on eligible patients, regardless of enrolment status.

Individuals admitted to study hospitals within the surveillance period with suspected or confirmed diagnosis of pneumonia who provided informed consent.

Radiologically confirmed (RAD) CAP.

Active surveillance between 1 January 2021 and 30 June 2023 identified at the three study sites 4319 adults with RAD-CAP that met eligibility criteria, of which 1479 (34.2%) were enrolled and included in the analysis for pathogen distribution. The main reason for non-enrolment was the inability to provide informed consent. Incidence estimates were based on 1254 study-eligible individuals admitted at the largest study site. SARS-CoV-2, S. pneumoniae, RSV or influenza were identified in 36.5%, 9.1%, 3.7% and 1.8% of patients with RAD-CAP, respectively. Serotypes included in the 20-valent pneumococcal conjugate vaccine were detected in 6.9% of RAD-CAP and 76.0% of pneumococcal CAP. The overall adjusted annual incidence of all-cause RAD-CAP over the study period was 490/100 000 (95% CI 461 to 521). The incidence of pneumococcal and RSV-related RAD-CAP increased 8.6-fold and 10.0-fold over the study period, resulting in an incidence of 60/100 000 (95% CI 45 to 75) and 30/100 000 (95% CI 19 to 41) in 2022/2023, respectively, while SARS-CoV-2 related RAD-CAP declined by 70% to 97/100 000 (95% CI 78 to 116).

Active pneumonia surveillance reported a high burden of RAD-CAP hospitalisations in Germany, especially among older adults. The resurgence of CAP due to RSV, S. pneumoniae or influenza, alongside maintained activity of SARS-CoV-2, was associated with an overall increase of RAD-CAP among adults.