LAUSR

Aim COVID-19 vaccine efficacy is high in older people, but declines after 4–6 months. Findings Booster doses are effective for restoring COVID-19 vaccine efficacy in older people. Message COVID-19 vaccine boosters generate higher protection than primary vaccination. 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 and 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.