Efficacy of COVID-19 vaccine booster doses in older people

Abstract Purpose. We provide here an updated analysis on efficacy of COVID-19 vaccine booster doses in older people (i.e., aged ≥80 years) based on ongoing Italian nationwide COVID-19 vaccination campaign. Methods. Data were obtained from the COVID-19 national integrated surveillance program, made available and regularly updated by the Italian National Institute of Health.Results. Compared to those who completed the COVID-19 vaccination cycle for ≥5 months (n=2.385.897), those receiving booster doses (n=1.549.747) had 75% lower risk of SARS-CoV-2 infection, 82-83% lower risk of COVID-19 hospitalization and ICU admission, and 81% lower risk of death. Administration of COVID-19 vaccine boosters generated also greater protection (between 63-87% higher) against all these same endpoints compared to early completing (i.e., <5 months; n=335.458) a primary COVID-19 vaccination cycle.Conclusions. The administration of COVID-19 vaccine booster doses is advisable for reducing the risk of morbidity and mortality in older people.