COVID-19 vaccination “fundamentally altered” the pandemic by saving nearly 20 million lives in the first year that vaccines were available, researchers found using a mathematical model.
“We wanted to conduct this study to understand how much worse the pandemic could have been without vaccination and, in doing so, demonstrate how many lives have been saved by generating and distributing vaccines as quickly as we did,” Oliver J. Watson, PhD, Schmidt Science Fellow at the MRC Centre for Global Infectious Disease Analysis of the Imperial College London, told Healio.
Watson and colleagues created a mathematical model of COVID-19 transmission, separately fitting vaccination to reported COVID-19 mortality and all-cause excess mortality. According to the study, the impact of COVID-19 vaccination programs was then determined by estimating the additional lives lost if no vaccines had been distributed.
Overall, the model estimated that vaccinations prevented 14.4 million COVID-19 deaths (95% credible interval [Crl], 13.7-15.9) in 185 countries and territories between Dec. 8, 2020, and Dec. 8, 2021, based on official reported COVID-19 deaths. This estimate grew to 19.8 million (95% Crl, 19.1-20.4) when researchers used excess deaths as an estimate of the “true extent of the pandemic,” representing a global reduction of 63% of total deaths during the first year of COVID-19 vaccination.
