COVID Experience Could Affect Fall Booster Immunity

Carolyn Crist

August 24, 2022

Editor's note: Find the latest COVID-19 news and guidance in Medscape's Coronavirus Resource Center.

Americans could have different immune responses to the latest COVID-19 vaccines this fall, depending on how they first experienced the coronavirus.

The original vaccines and boosters, as well as prior infections, have created different layers of immunity in cities and communities across the nation. The version of the virus that people were first exposed to will likely dictate how they respond to new vaccines and variants, according to The Washington Post .

"There are no cookie-cutter answers here," John Moore, PhD, a professor of microbiology and immunology at Weill Cornell Medicine, told the newspaper.

"An Omicron infection after vaccination doesn't mean you're not going to get another one a bit further down the road," he said. "How long is a bit further down the road?"

Known as "original antigenic sin" in the scientific community, the concept means that first exposure can direct later responses in the body. People's immune systems are responding in different ways, which has prompted questions about reinfections, updated booster shots, and protection against new variants.

On the positive side, the concept helps to explain why vaccines based on the original coronavirus strain continue to protect people against severe disease and hospitalization, the newspaper reported.

At the same time, it may also mean that the newest fall booster shots could have limited benefits because people's immune systems are focused on the first experience with the virus, whether through infection or vaccination.

"We may have gotten about as much advantage out of the vaccine, at this point, as we can get," Barney Graham, MD, who has worked on coronavirus vaccines and now focuses on global health equity at the Morehouse School of Medicine in Atlanta, told the Post.

Graham noted that the current vaccines are doing their job of keeping people out of hospitals. Updated vaccines will have some benefits, though they may be limited.

"We can tweak it and maybe evolve it to match circulating strains a little better," he said. "It will have a very small, incremental effect."


The Washington Post: "Your first brush with coronavirus could affect how a fall booster works."


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