Who Benefits Most From COVID Boosters? New Study Gives Answers

MONDAY, Feb. 13, 2023 (HealthDay News) -- COVID-19 booster shots appear to benefit folks 50 and older but less so for younger people, a new study suggests.

For the study, researchers ran a statistical analysis using death rates from COVID, and looked at the vaccines' effectiveness in protecting people from dying of the disease. While they were found to be very effective among older people, the study noted that boosters made little difference in younger folks because they're least likely to die from the infection anyway.

Senior researcher Bernard Black is a law professor at Northwestern University's Pritzker School of Law in Chicago who specializes in health policy. He pointed out that the study only looked at deaths from COVID and did not consider infections the vaccine may have prevented or made less severe.

Still, for younger people the booster may be of less benefit, he suggested.

"There isn't evidence of a [death] benefit in younger people," Black said.

Although millions of Americans have gotten the initial doses of a COVID vaccine, only about 16% of those eligible for booster shots have gotten them, according to the U.S. Centers for Disease Control and Prevention.

The CDC recommends that everyone 6 months and older get the COVID vaccine and keep up with boosters.

With the CDC and the U.S. Food and Drug Administration poised to recommend yearly COVID shots, Black believes the message should be focused on folks in their 60s and older, for whom the protection against dying is greatest.

"We don't know enough to know whether to recommend an annual COVID shot below age 60," he said. "From everything I know, above a 60, sure; in your 50s, probably. Below that, I'd say we just don't know."

Maybe, Black said, if public health messaging said, "You are someone who really needs it," more people who really need the booster would get it.

For the study, Black and his colleagues combed death and vaccination records for 722,000 adults in Milwaukee County, Wisc., from Jan. 1, 2021 to June 30, 2022.

They said their study is the first to control for the tendency of people who get vaccinated to be healthier than unvaccinated folks by comparing death rates from COVID and other natural causes.

Like other research, this study found that protection from the initial two vaccine doses waned over time, especially against the highly contagious Omicron variant.

Compared to unvaccinated people, the risk of dying from COVID during the six-month Omicron wave for folks who had two doses of an mRNA vaccine was 42% for 40- to 59-year-olds; 27% for 60- to 79-year-olds; and 46% for people 80 and older. (0% indicates full protection; 100% means none.)

A booster dose substantially reduced the risk of death -- bringing it down to 11% for people aged 60 and older, the study found. The shot also protected against death for people in their 50s.

The vaccines are really good, "but let's not claim they're better than they are," Black said. "And let's not tell younger people that it's super critical that you get boosted because it's not. Is it a good idea? Yeah. But is it critical? No more than a flu shot is."

Dr. Peter Silver, senior vice president and associate chief medical officer at Northwell Health in New Hyde Park, N.Y., reviewed the findings.

"The study did not look at hospitalizations or severe illness or the effect of living with somebody who may be vulnerable -- all the other reasons that you'd want a younger person to be vaccinated," Silver said.

"We know that younger and healthier people are at lower risk for dying from COVID than older people or people with complex medical conditions, but that doesn't mean that they don't get really sick or that they don't transmit it to other people who may be vulnerable," Silver added.

His advice: Get vaccinated and get boosted. The vaccines provide protection even though it wanes over time, he said.

"But they still provide protection, especially against severe illness, hospitalizations and death, and there's no evidence of any significant risk of the vaccines," Silver said.

He added that misinformation about the vaccine is widespread, including claims of ill effects such as genetic reprogramming.

"None of that's really been shown to be true," Silver said. "It's safe for all populations, and it helps keeps us safer."

The findings were published online Feb. 7 in the journal Vaccines.

More information

Learn more about COVID vaccines at the U.S. Centers for Disease Control and Prevention.

SOURCES: Bernard Black, JD, professor, Northwestern University Pritzker School of Law, Chicago; Peter Silver, MD, senior vice president and associate chief medical officer, Northwell Health, New Hyde Park, N.Y.; Vaccines, Feb. 7, 2023, online