The pandemic has claimed over 1 million American lives, and per capita, the US is one of the countries which has suffered the highest number of fatalities (despite being a rich country and having advanced medical tools). Now, a new analysis has found that almost a quarter-million Americans could have been saved if they had just taken the vaccine.

We’ve known for over a year that approved vaccines against COVID-19 are safe and effective. We’ve seen large-scale studies coming both from the development companies and independent sources, and all the well-documented information points in the same direction: the protection vaccines offer is substantial and far greater than the side effects.

But despite this, vaccine hesitancy took a big toll. In a new study, researchers from Kaiser Family Foundation (a non-profit that publishes analyses on American healthcare) calculated that from June 2021 through March 2022, a whopping 234,000 lives could have been saved with a primary series of COVID-19 vaccines. This figure makes up some 60% of all adult COVID-19 deaths since June 2021, when vaccines became widely available — and around a quarter of US COVID-19 deaths since the pandemic began.

To reach this conclusion, the researchers first analyzed deaths among adults in the months after vaccines were widely available (June 2021 through March 2022), including only adults because children represent a small part of COVID-19 deaths (and vaccines were not available for some groups over that period). In total, they counted 389,000 adult COVID-19 deaths since June 2021.

To then calculate how many of these could have been prevented by vaccination, they then calculated the share of COVID-19 deaths among those who were unvaccinated (ranging from 86% in June 2021, down to 58% in January 2022) and applied this to all adult COVID-19 deaths. They also corrected for vaccine effectiveness, because while very efficient, vaccines don’t offer 100% protection.

The study authors mention limitations of their work; most notably, the study was carried out on 25 CDC jurisdictions which were assumed to be nationally representative. In addition, the study didn’t look at the effect of boosters in-depth (which may be significant, especially against Omicron). The study also isn’t yet peer-reviewed.

However, the study clearly points out what researchers have been saying for months: vaccine hesitancy costs lives — a lot of them. It’s a tragedy that so many deaths that were preventable happened, and, to a lesser extent, this still continues to happen.

Unvaccinated people in the US now represent a small share of the overall population, but a majority of COVID-19 deaths. Research has shown that against the newly mutated Omicron strain (with its substrains), a booster is also very important.

We’ve made important progress against the pandemic, but we’re still not out of the woods just yet. As long as the virus continues to mutate and much of the world isn’t vaccinated, there’s still a risk out there.