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

• Published in: Environmental research Vol. 204; no. Pt C; p. 112342
• Main Authors: Pastorino, Roberta, Pezzullo, Angelo Maria, Villani, Leonardo, Causio, Francesco Andrea, Axfors, Cathrine, Contopoulos-Ioannidis, Despina G., Boccia, Stefania, Ioannidis, John P.A.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Inc 01.03.2022; Published by Elsevier Inc
• Subjects: Adolescent; Adult; Age Distribution; Aged; Child; Child, Preschool; COVID-19; COVID-19 Vaccines; Death; Humans; Infant; Infant, Newborn; Middle Aged; Population data; SARS-CoV-2; Vaccination; Vaccine Efficacy; Young Adult; COVID-19; Death; Population data; Vaccination
• ISSN: 0013-9351; 1096-0953
• DOI: 10.1016/j.envres.2021.112342

Most countries initially deployed COVID-19 vaccines preferentially in elderly populations. We aimed to evaluate whether population-level vaccine effectiveness is heralded by an increase in the relative proportion of deaths among non-elderly populations that were less covered by vaccination programs. We 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 (1) countries with low vaccination rates; (2) countries with age-independent vaccination policies; and (3) countries with standard age-dependent vaccination policies. Countries 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 proportion ratio 1.32 [95 CI% 1.24–1.41] and 1.35 [95 CI% 1.26–1.44)]. No such change was seen on average in countries with age-independent vaccination policies (1.05 [95 CI% 0.78–1.41 and 0.97 [95 CI% 0.95–1.00], respectively) and limited vaccination (0.93 [95 CI% 0.85–1.01] and 0.95 [95 CI% 0.87–1.03], respectively). Proportion 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. The substantial shift in the age distribution of COVID-19 deaths in countries that rapidly implemented vaccination predominantly among elderly provides evidence for the population level-effectiveness of COVID-19 vaccination and a favorable evolution of the pandemic towards endemicity with fewer elderly deaths. •There was a shift towards younger age strata for COVID-19 deaths in many countries in the first 5 months of deployment of COVID-19 vaccines.•This age shift was not noticed in countries that had low vaccination coverage or did not prioritize vaccination in the elderly.•The age shift in COVID-19 deaths provides strong evidence for the effectiveness of vaccination and the evolution of the pandemic towards endemicity.