How many lives has the Covid-19 vaccine saved? Some 20 million across the globe in just the first year of vaccination (December 8, 2020, to December 8, 2021), according to a recent report in The Lancet Infectious Diseases. The data used in the analysis—which applied mathematical modeling to determine the results—came from 185 countries and territories with populations of 90,000 or more (excluding China). Without vaccines, the researchers estimated that there would have been nearly 32 million Covid-related deaths over that year span.

This 20-million number includes not just deaths averted from Covid itself (some 14.4 million) but also deaths indirectly related to Covid (5.4 million), which gives a fuller picture of the pandemic’s lethal impact. Indirect Covid deaths include those that were inaccurately attributed to illnesses other than Covid, as well as deaths caused, for instance, by Covid-related disruptions in health care. In effect, vaccination more than halved the potential worldwide death toll from Covid in that first year alone.

The number of lives saved would have been even greater if 40 percent of the population of each country had been vaccinated by the end of 2021. That was the World Health Organization’s target, but it wasn’t met due to inadequate access to vaccines in poorer nations, vaccine misinformation, and other shortfalls. Even the 20 percent vaccine target goal set by COVAX—a global collaboration established to hasten the development, production, and equitable access to Covid testing, treatment, and vaccines—was not met.

The true number of Covid deaths—and therefore lives saved—is difficult to pinpoint, and modeling methods used in studies like this are subject to great variability. Still, the authors of this study concluded that their results “highlight the substantial impact that vaccination has had on the trajectory of the Covid-19 pandemic.” But they also emphasize that improvements are essential in combating inequities in vaccine distribution across the globe.