Clinical effectiveness of 13-valent and 23-valent pneumococcal vaccination in middle-aged and older adults: The EPIVAC cohort study, 2015–2016

Abstract

BackgroundClinical benefits using the 23-valent pneumococcal polysaccharide vaccine (PPsV23) or the 13-valent pneumococcal conjugate vaccine (PCV13) in adults are controversial. This study investigated clinical effectiveness for both PPsV23 and PCV13 in preventing pneumonia among middle-aged and older adults. MethodsPopulation-based cohort study involving 2,025,730 persons ≥50 years in Catalonia, Spain, who were prospectively followed between 01/01/2015 and 31/12/2016. Primary outcomes were hospitalisation from pneumococcal or all-cause pneumonia and main explanatory variable was PCV13/PPsV23 vaccination status. Multivariable Cox regression models were used to estimate vaccination effectiveness adjusted for age and baseline-risk conditions. ResultsCohort members were followed for 3,897,151 person-years (17,496 PCV13 vaccinated and 1,551,502 PPsV23 vaccinated), observing 3259 pneumococcal pneumonias (63 in PCV13 vaccinated, 2243 in PPsV23 vaccinated) and 24,079 all-cause pneumonias (566 in PCV13 vaccinated, 17,508 in PPsV23 vaccinated). Global incidence rates (per 100,000 person-years) were 83.6 for pneumococcal pneumonia (360.1 in PCV13 vaccinated, 144.6 in PPsV23 vaccinated) and 617.9 for all-cause pneumonia (3235.0 in PCV13 vaccinated, 1128.5 in PPsV23 vaccinated). In the multivariable analyses, the PCV13 appeared significantly associated with an increased risk of pneumococcal pneumonia (hazard ratio [HR]: 1.52; 95% confidence interval [CI]: 1.17–1.97; p = 0.002) and all-cause pneumonia (HR: 1.76; 95% CI: 1.61–1.92; p < 0.001) whereas the PPsV23 did not alter the risk of pneumococcal pneumonia (HR: 1.08; 95% CI: 0.98–1.19; p = 0.132) and slightly increased the risk of all-cause pneumonia (HR: 1.17; 95% CI: 1.13–1.21; p < 0.001). In stratified analyses focused on specific target population subgroups (i.e., elderly people, at-risk and high-risk individuals), protective effects of vaccination did not emerge either. ConclusionData does not support clinical benefits from pneumococcal vaccination (nor PCV13 neither PPsV23) against pneumonia among Catalonian adults in the current era of universal PCV’s childhood immunisation.