The study, co-authored by Marcia Castro, Andelot Professor of Demography and chair of the Department of Global Health and Population at Harvard T.H. Chan School of Public Health, found a rapid decline in mortality among those 80 years and older after Brazil started vaccinating its elderly population in mid-January 2021.
Up until February 2021, deaths among people 80 and older consistently accounted for between 25%-30% of all COVID-19 deaths reported in Brazil. The country launched a vaccine campaign targeted at the elderly, and 95% of Brazilians 80 and older have now been vaccinated. As a result, the proportion of COVID-19 deaths attributed to that group fell rapidly and was under 13% of all COVID-19 deaths reported in the country as of early May.
Similar declines have been seen in people aged 70–79 years as vaccination rates increase.