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COVID-19 vaccination rollout in US prevented nearly 300,000 deaths, study finds

Julio Valiente received a COVID-19 vaccine from registered nurse Cynthia Pierre at a mobile clinic outside of Market Basket in Chelsea.
Julio Valiente received a COVID-19 vaccine from registered nurse Cynthia Pierre at a mobile clinic outside of Market Basket in Chelsea.Erin Clark/Globe Staff

The COVID-19 vaccination rollout in the United States prevented hundreds of thousands of deaths and hospitalizations and averted a spring surge as more transmissible variants emerged, according to a new study.

If there had not been a vaccination program, researchers estimated there would have been an additional 279,000 deaths and up to 1.25 million more hospitalizations in the country by the end of June 2021, according to the study, published Wednesday from the Yale School of Public Health and the Commonwealth Fund.

As of Thursday, more than 67 percent of American adults have received at least one dose of a COVID-19 vaccine, according to data from the Centers for Disease Control and Prevention.


The researchers found that the spring wave that failed to materialize could have been even deadlier than the winter surge, which at its height saw 4,000 daily deaths nationwide. Their model found the daily death rate could have climbed as high as 4,500.

Those additional deaths would have been caused by an increase in the spread of the Alpha variant first detected in the United Kingdom, the researchers found.

Additionally, if the rollout had achieved only half the daily pace, there would have been nearly 121,000 additional deaths and more than 450,000 additional hospitalizations, the study found. There also would have been an additional 26 million cases without a vaccination program, and 22 million cases if the pace of the rollout had been half as effective, according to the study.

As of Thursday, the United States has recorded more deaths and infections due to the virus than any other country in the world with more than 600,000 deaths and more than 33 million cases, according to data collected by Johns Hopkins University. On Wednesday, the world surpassed 4 million COVID-19 deaths, according to the university.


To study the effectiveness of the vaccination campaign, researchers simulated two different trajectories of the country’s hospitalizations, cases, and deaths: One with no vaccination program and one with the actual pace reduced by half. They then compared those models to what actually happened: A rapid vaccination rollout starting in mid-December of last year.

The study notes that the speed of the campaign appears to have prevented a spring surge that would have been fueled by the Alpha variant, along with the Gamma variant first detected in Brazil. Researchers warned the highly transmissible Delta variant, which continues to spread and is now the dominant strain in some states, will remain a threat to unvaccinated people in the months ahead.

“Ominously, the Delta variant, linked to a resurgence of COVID-19 infections in India, Nepal, and other southeast Asian countries, is threatening to shift the course of the pandemic in the US,” the researchers wrote. “With an even higher transmissibility than the Alpha variant, the Delta variant currently accounts for more than 40 percent of positive tests and is already establishing dominance in some US states.”

The CDC said this week that the Delta variant has accounted for more than half of all new COVID-19 infections in the US.

Amanda Kaufman can be reached at amanda.kaufman@globe.com. Follow her on Twitter @amandakauf1.