McNamara LA, Wiegand RE, Burke RM, et al. - Among older adults, decreases in COVID-19 cases, emergency department visits, as well as in hospital admissions were observed in relation to the initial roll-out of the US COVID-19 vaccination program.

• COVID-19 vaccines in the USA were accessible in mid-December, 2020, with adults aged 65 years and older among the first groups prioritized for vaccination.

• The national-level effect of the initial phases of the US COVID-19 vaccination program on COVID-19 cases, emergency department visits, hospital admissions, and deaths in adults aged 65 years and older were analyzed.

• Relative reductions of 53% and 62% were demonstrated by the ratio of relative changes (comparing COVID-19 incidence ratio in post-vaccine vs pre-vaccine periods) in the adults aged 65 to 74 years and 75 years and older, respectively, vs those aged 50 to 64 years.

• Similar outcomes were obtained for emergency department visits, with relative reductions of 61% for adults aged 65 to 74 years and 77% for those aged 75 years and older vs adults aged 50 to 64 years.

• In those aged 60 to 69 years, aged 70 to 79 years, and aged 80 years and older, reductions in hospital admissions by 39%, 60%, and 68%, respectively, were noted when compared with adults aged 50 to 59 years.

• Reduction in COVID-19 deaths was also evident (by 41%, in adults aged 65–74 years and by 30%, –47 to 66 in those aged ≥75 years, vs adults aged 50 to 64 years), however, the magnitude of the effect of vaccination roll-out on deaths was not clear.