Evolution of hospitalizations of adults for Community-Acquired Pneumonia in Portugal and the impact of pediatric pneumococcal vaccination

In Portugal, universal and free paediatric pneumococcal vaccination began in January 2015 with the inclusion of the 13-valent conjugate vaccine in the National Immunisation Programme (NIP). To characterise the evolution of adult hospitalisations for Community-Acquired Pneumonia (CAP) and to assess the impact of children pneumococcal vaccination on adult hospitalisations, we conducted a retrospective analysis of all adult hospitalisations in the National Health Service in Portugal from 2010 to 2019. A comparison with the period from 2000 to 2009 was also performed. The analysis utilised coded information from official databases. It included discharge hospital records of all individuals aged 18 years or older admitted with a primary diagnosis of CAP between 1 January 2010, and 31 December 2019. During the study period, there were 462 910 hospitalisations for CAP, which accounted for 6.2% of the total hospitalisations for all causes, with an incidence rate of 5.38 hospitalisations per 1 000 persons per year. Most admitted patients were male (54%), with an average and median age of 76.7 and 81 years, respectively. Approximately half of the patients (50.2%) were over 80 years old. In comparison with 2000 to 2009, there was a significant increase in the absolute number of hospitalisations, the average age, and the incidence among older patients. After the implementation of paediatric pneumococcal vaccination in the NIP, there was a sustained and significant decrease in the rate of hospitalisations for CAP per 1 000 persons per year among individuals aged 65 years or older. These findings contribute to demonstrating the indirect benefits of universal paediatric pneumococcal vaccination on adult hospitalisations for CAP, as well as the importance of healthy ageing and preventive measures.