Respiratory Syncytial Virus Risk Assessment in Adults: Implications for Vaccine Recommendations Beyond Age.

Background: Respiratory syncytial virus (RSV) causes hospitalization in older adults and those with preexisting medical conditions. Three RSV vaccines are now licensed for all adults but not recommended for persons age <60 years with risk factors for RSV hospitalization. We therefore assessed the relationship of preexisting medical conditions to age-specific RSV hospitalization incidence and severe outcomes. Methods: Adults age ≥18 years hospitalized over 3 winters (2017-2020) with polymerase chain reaction-confirmed RSV were enrolled in Rochester and New York City, NY. Population-based incidence was estimated by race and ethnicity for 4 age groups: 18-44, 45-64, 65-74, and ≥75 years. A general linear model assessed variables associated with 2 outcomes: (1) composite of intensive care unit admission and/or in-hospital mortality and (2) all-cause 6-month mortality. Results: Adults of all ages with congestive heart failure (CHF), coronary artery disease, chronic obstructive pulmonary disease (COPD), and diabetes were more likely to be hospitalized with RSV (incidence rate ratio, 13.66, 8.24, 5.85, and 5.35, respectively), and asthma, obesity, and immunosuppression were more prevalent among younger adults age ≤65 years. Mean annual RSV hospitalization incidence was 2.5-fold higher for Black adults age 18-44 years and 8-fold higher for those age 45-64 years compared with other races. Hispanic adults had a 2-3-fold higher incidence of hospitalization in each age stratum compared with non-Hispanics. COPD conferred a 1.9-fold higher risk of intensive care unit admission or in-hospital mortality (97.5% CI, 1.27-2.68), and both COPD and CHF increased risk of 6-month all-cause mortality. Age ≥65 years was not associated with either outcome. Conclusions: Future RSV vaccine recommendations should consider the impact of preexisting conditions and racial and ethnic differences in age-related RSV hospitalization.