Vax Campaign Averted Nearly 140,000 US Deaths Through Early May: Study

Ken Terry

August 18, 2021

From mid-December 2020 through early May 2021, there were 139,393 fewer deaths from COVID-19 and about 3.1 million fewer confirmed cases in the United States than would have been expected without the COVID-19 vaccination campaign, finds a new report published online today in Health Affairs.

New York had 11.7 fewer COVID-19 deaths per 10,000 adults and Hawaii had 1.1 fewer deaths per 10,000 than would have occurred without vaccinations, the study shows. The rest of the states fell somewhere in between, with the average state experiencing five fewer COVID-19 deaths per 10,000 adults.

At a national level, this means that instead of the 550,000 COVID-19 deaths that occurred by early May, there would have been 709,000 deaths in the absence of a vaccination campaign, according to the study.

Researchers from RAND and Indiana University created models to estimate the number of COVID-19 deaths that would have happened without vaccinations. The difference between the actual number of deaths and those estimates provides a measure of the number of COVID-19 deaths averted by the vaccination campaign.

Information about vaccine doses administered in each state came from the Bloomberg COVID-19 Vaccine Tracker, and data on COVID-19 deaths for each state came from The New York Times' Coronavirus (COVID-19) Data in the United States database.

The study spanned the period from December 21, 2020 to May 9, 2021. The US Food and Drug Administration issued its first emergency use authorization (EUA) for a COVID-19 vaccine to Pfizer/BioNTech on December 11, followed by an EUA for the Moderna vaccine on December 18 and one for Johnson & Johnson's vaccine on February 27, 2021.

Varied by State

There were wide variations in the speed and extent of the vaccination campaigns in various states, the researchers found. For example, West Virginia was the first state to reach 10 doses per 100 adults, reaching that goal on January 16, 2021, and Idaho was the last state to hit that mark, on February 4, 2021. Alaska was the first to reach 20 doses per 100 adults, on January 29, and Alabama was the last to do it, on February 21.

On May 6, California was the first state to administer 120 doses per 100 adults, but many states have still not reached that milestone.

The median number of days between the milestones of 10 and 20 doses per 100 adults was 19 days, and the median number of days between 20 and 40 doses per 100 adults was 24 days.

Hard to Establish Causality

The researchers emphasized that "establishment of causality is challenging" in comparing individual states' vaccination levels with their COVID-19 mortality rates.

Aside from the study being observational, they pointed out, the analysis "relied on variation in the administration of COVID-19 vaccines across states…Vaccine administration patterns may be associated with declining mortality because of vaccine prevention of deaths and severe complications as state-level vaccine campaigns allocated initial doses to the highest-risk populations with the aim of immediately reducing COVID-19 deaths."

Nevertheless, the authors note, "clinical trial evidence has shown that COVID-19 vaccines have high efficacy. Our study provides support for policies that further expand vaccine administration, which will enable larger populations to benefit."

Study Confirms Vaccine Benefit

Aaron Glatt, MD, chair of medicine at Mount Sinai South Nassau in Oceanside, New York, and a spokesman for the Infectious Disease Society of America, told Medscape Medical News that the study is important because it confirms the benefit of COVID-19 vaccination.

Regardless of whether the study's results are statistically valid, he said, "I don't think anyone can argue the benefit isn't there. It's a question of how important the benefit is."

Glatt is not surprised that there are variations across states in the number of COVID-19 deaths averted through vaccination. "Clearly, in states where there was a lot of disease, a significant amount of vaccination is going to impact that tremendously."

The authors note their paper has some limitations. For one thing, they couldn't determine what share of the estimated reduction in COVID-19 deaths was a result of the proportion of the population that was vaccinated or had antibodies and what share was a result of lower population-level risk for COVID-19 transmission.

Vaccination vs Natural Immunity

In addition, the researchers weren't able to identify the roles of vaccination, natural immunity, and changes in mobility in the numbers of COVID-19 deaths.

Glatt says that's understandable, since this was a retrospective study and the researchers didn't know how many people had been infected with COVID-19 at some point. Moreover, he adds, scientists don't know how strong natural immunity from prior infection is, how long it endures, or how robust it is against new variants.

"It's clear to me that there's a benefit in preventing the second episode of COVID in people who had a first episode of COVID," he said. "What we don't know is how much that benefit is and how long it will last."

The researchers also didn't know how many people had gotten both doses of the Pfizer or the Moderna vaccine, and how many of them had received only one. This is an important piece of information, Glatt said, but the lack of it doesn't impair the study's overall finding.

"Every vaccine potentially prevents death," he stressed. "The more we vaccinate, the more deaths we'll prevent. We're starting to see increased vaccinations again. There were a million of them yesterday. So people are recognizing that COVID hasn't gone away, and we need to vaccinate more people. The benefit from the vaccination hasn't decreased. The more we vaccinate, the more the benefit will be."

Health Affairs. Published online August 18, 2021. Abstract

For more news, follow Medscape on Facebook, Twitter, Instagram, YouTube, and LinkedIn