Routine infant vaccination of pneumococcal conjugate vaccines has decreased pneumonia across all age groups in Northern Spain

Since the early 2000s, pneumococcal conjugate vaccines (PCVs) have been shown to be effective in the prevention of pneumonia and invasive pneumococcal diseases. In 2011, the Galician region incorporated PCV in the routine infant immunization, the very first stable program in Spain. We aim to assess direct and indirect benefits of PCV vaccination on all-cause pneumonia in the region across different age groups using an ecological study design. For this, we calculated the annual hospitalization rates using a hospital-based disease registry. We identified all-cause pneumonia, pneumococcal pneumonia and pneumococcal invasive diseases within the registry. Hospitalization rates were computed and compared across three study periods: pre-vaccination (1998-2003), early-vaccination (2005-2009) and routine-vaccination (2011-2015). Across Northern Spain, we identified 114,873 all-cause pneumonia hospitalizations, of which 24,808 were further diagnosed with pneumococcal pneumonia. The majority were elderly > 64 years (67.3%). Hospitalizations from all-cause pneumonia had a net increase from 20.6 (pre-PCV) and 21.4/10,000 (early) to 28.4/10,000 (routine) (+32.7%, p