Change in age distribution of COVID-19 deaths with the introduction of COVID-19 vaccination

BackgroundMost countries initially deployed COVID-19 vaccines preferentially in elderly populations. Population-level vaccine effectiveness may be heralded by an increase in the proportion of deaths among non-elderly populations that were less covered by vaccination programs. MethodsWe collected data from 40 countries on age-stratified COVID-19 deaths during the vaccination period (1/14/2021-5/31/2021) and two control periods (entire pre-vaccination period and excluding the first wave). We meta-analyzed the proportion of deaths in different age groups in vaccination versus control periods in countries with low vaccination rates; (2) countries with age-independent vaccination policies; and (3) countries with standard age-dependent vaccination policies. FindingsCountries that prioritized vaccination among older people saw an increasing share of deaths among 0-69 year old people in the vaccination versus the two control periods (summary prevalence ratio 1{middle dot}32 [95 CI% 1{middle dot}24-1{middle dot}41] and 1{middle dot}35 [95 CI% 1{middle dot}26-1{middle dot}44)]. No such change was seen on average in countries with age-independent vaccination policies (1{middle dot}05 [95 CI% 0{middle dot}78-1{middle dot}41 and 0{middle dot}97 [95 CI% 0{middle dot}95-1{middle dot}00], respectively) and limited vaccination (0{middle dot}93 [95 CI% 0{middle dot}85-1{middle dot}01] and 0{middle dot}95 [95 CI% 0{middle dot}87-1{middle dot}03], respectively). Prevalence ratios were associated with the difference of vaccination rates in elderly versus non-elderly people. No significant changes occurred in the share of deaths in age 0-49 among all 0-69 deaths in the vaccination versus pre-vaccination periods. InterpretationThe substantial shift in the age distribution of COVID-19 deaths in countries that rapidly implemented vaccination predominantly among elderly may herald the population level-effectiveness of COVID-19 vaccination and a favorable evolution of the pandemic towards endemicity with fewer elderly deaths. FundingThis study received no specific funding.