WEDNESDAY, July 6, 2022 (HealthDay News) — The U.S. COVID-19 vaccination program has cut the expected death rate from the coronavirus by as much as 58%, saving hundreds of thousands of lives during the first two waves of the pandemic, a new study says.
Computer models estimate that vaccines prevented 235,000 COVID deaths in the United States between December 2020 and September 2021, reducing the death toll from both the original virus and the Delta variant.
Vaccination also prevented 1.6 million hospitalizations and 27 million COVID infections, according to data generated by the U.S. Centers for Disease Control and Prevention. The findings appear on July 6 in JAMA network opened †
The results “reinforce the idea that COVID vaccination clearly works,” said Dr. William Schaffner, medical director of the National Foundation for Infectious Diseases in Bethesda, Maryland. “It works very successfully to prevent deaths. And if more people had accepted vaccination, we could have prevented even more deaths.”
In reality, vaccines have likely saved even more lives than estimated here, said lead researcher Molly Steele, a CDC epidemiologist.
“These estimates only account for benefits among those who have been vaccinated and do not account for benefits to unvaccinated individuals from reducing disease transmission,” Steele said.
“Therefore, our estimates of the impact of vaccines are conservative,” she said. Either way, these estimates help illustrate the benefits of COVID-19 vaccines in reducing infections and hospitalizations and saving lives.”
So far, no one has determined exactly how many COVID illnesses and deaths have been prevented by the three vaccines available in the United States, CDC researchers said in background notes.
To put a stop to that, researchers developed a model that takes into account the estimated risk of infection, hospitalizations and death for specific age groups among the unvaccinated. They then incorporated the protective effects of vaccination into their numbers.
They found that between December 2020 and September 2021, vaccination prevented 30% of all expected COVID infections, 33% of all expected hospitalizations and 34% of all expected adult deaths.
That includes preventing 154,000 deaths among people age 65 or older, 66,000 deaths among people ages 50 to 64 and 14,000 deaths among people ages 18 to 49, estimates showed.
“COVID-19 vaccination may have reduced the overall impact of COVID-19 by about a third,” Steele said. “This means that illness and deaths would have increased by 30% without vaccination. So if more people were vaccinated against COVID-19, we would expect a further decline in infections, hospitalizations and deaths.”
In addition, that protection grew month by month as the vaccination program rolled out and more people were vaccinated against COVID, researchers say.
In September 2021, vaccines prevented 58% of expected deaths and 56% of expected hospitalizations, as well as 52% of expected infections.
“The findings are not surprising. The COVID-19 vaccines are undeniably the best way to prevent the serious consequences of infection, including death,” said Dr. Amesh Adalja, senior scientist at the Johns Hopkins Center for Health Security.
“The goal of the vaccination program, with first-generation vaccines, was to shift the disease spectrum to the milder side, to decouple cases of deaths,” Adalja said. “That’s clearly what the data has shown, as illustrated by this modeling study.”
Steele added that the study doesn’t tell the whole story as it is based on data collected through September 2021.
Therefore, the study “does not reflect more recent updates regarding COVID-19 vaccination, including the approval of booster doses for most age groups, and the expansion of COVID-19 vaccines for children 6 months and older,” Steele said.
“As more people get vaccinated and get boosters, additional hospitalizations and deaths from COVID-19 will be prevented,” Steele added.
Improved COVID vaccines being developed by Pfizer and Moderna are expected to improve that protection even more, Schaffner said.
“This fall, we are expected to have to hand over COVID vaccine 2.0, as I like to say,” Schaffner said. “It will be a bivalent vaccine. It will have the antigen we are using now, but will have in addition an antigen related to Omicron and its newest variants.”
The missed opportunity lies in the fact that clinical trials had shown that the vaccines could reduce the risk of death from COVID by up to 94%, according to an editorial published with the study.
One in three Americans remain unvaccinated, the editorial noted, and new strategies are needed to reach those people.
“Without evidence-based strategies, we wonder why the same COVID-19 vaccines, which can reduce the risk of death by up to 94%, only managed to prevent 58% of deaths,” the editors wrote.
The US Centers for Disease Control and Prevention has more about COVID vaccines.
SOURCES: William Schaffner, MD, medical director, Bethesda, Md.-based National Foundation for Infectious Diseases; Molly Steele, PhD, MPH, epidemiologist, US Centers for Disease Control and Prevention; Amesh Adalja, MD, senior scientist, Johns Hopkins Center for Health Security; JAMA network openedJuly 6, 2022