Examining the Association between Frailty and Antibody Neutralization of SARS-CoV-2: A Multisite Retrospective Cohort Study

Despite high vaccination rates, older adults are most susceptible to COVID-19 and severe disease.1 It is estimated that neutralizing antibodies provide protective immunity against symptomatic SARS-CoV-2 infection in young, healthy adults.2 Frailty is a potential modifier of vaccine immunogenicity and protective immunity in older adults.3 Prior studies with relatively small cohorts have provided mixed evidence regarding the association of frailty and SARS-CoV-2 neutralizing antibodies, with some observing frail older adults have poorer humoral immune responses to vaccinations, whereas others report no impact of frailty.