Burden of lower respiratory tract infections preventable by adult immunization with 15- and 20-valent pneumococcal conjugate vaccines in the United States

BackgroundUpdated 2022 recommendations indicate all US adults aged ≥65 years and adults aged MethodsWe estimated the incidence of LRTI cases and associated hospital admissions among enrollees of Kaiser Permanente Southern California health plans from 2016-19. We used a counterfactual inference framework to estimate excess LRTI-associated risk of death up to 180 days after diagnosis. We used prior estimates of PCV13 effectiveness against all-cause and serotype-specific LRTI to model potential direct effects of PCV15/20 by age group and risk status.ResultsUse of PCV15 and PCV20, respectively, could prevent 89.3 (95% confidence interval: 41.3-131.8) and 108.6 (50.4-159.1) medically-attended LRTI cases per 10,000 person-years; 21.9 (10.1-32.0) and 26.6 (12.4-38.7) hospitalized LRTI cases per 10,000 person-years; and 7.1 (3.3-10.5) and 8.7 (4.0-12.7) excess LRTI-associated deaths per 10,000 person-years. Among at-risk adults aged ConclusionsOur findings suggest recent recommendations including PCV15/20 within adult pneumococcal vaccine series may substantially reduce LRTI burden.Key pointsUse of PCV15/20 among US adults aged ≥65 years may prevent 521,000-626,000 LRTI cases, 127,000-154,000 hospitalizations, and 50,000-61,000 excess deaths, annually.Updated recommendations for PCV15/20 among adults aged