Monitoring of community-acquired pneumonia hospitalisations before the introduction of pneumococcal conjugate vaccine into Polish National Immunisation Programme (2009–2016): A nationwide retrospective database analysis

•CAP causes the hospitalisation of ~1 million people in the European Union each year.•Universal mass vaccination against IPD reduced the burden of CAP in many countries.•In January 2017, Poland introduced PCV into their national immunisation programme.•This is the 1st national study monitoring CAP hospitalisations pre-PCV introduction.•These baseline data will allow to assess the impact of the new vaccination policy. Community-acquired pneumonia (CAP) is a common infection with significant morbidity and mortality. In January 2017, Poland introduced pneumococcal conjugate vaccine (PCV) into their national immunisation programme to protect children against invasive pneumococcal disease. This study was designed to investigate pneumonia-related hospitalisation rates and trends from 2009 to 2016 prior to the introduction of nationally funded PCV vaccination. Using national public statistic data available from the National Institute of Public Health – National Institute of Hygiene, annual hospitalisation rates for pneumonia were analysed, categorised by aetiology and age (