People who have had COVID-19 may only need to get vaccinated once, studies show

Six recent studies suggest that people who have already contracted COVID-19 may not need to receive a second dose of the vaccine.

The federal government has not changed its recommendation for a second dose, but studies examining the immune response show that if a first hit gives a huge boost to people who have recovered from COVID-19, the second hit does. little difference.

“I think that makes perfect sense,” said Dr. Paul Offit, director of the Vaccine Education Center at Children’s Hospital of Philadelphia.

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For someone who has had COVID-19, the first shot is like a COVID-19 naive person getting a booster – they even have the side effects of someone receiving a second dose of the vaccine, he said. .

“You can reasonably say that people who can prove that they have been infected – that is, they have antibodies to the virus – could reasonably be given only one dose,” Offit said.

There is no danger in getting a second shot, for someone who has had COVID-19, said Florian Krammer, who led one of the recent studies. But that may not be beneficial for the time and stress it takes to make a reservation, travel to and from a vaccination site and watch the needle enter.

And every person who doesn’t need a second hit means someone else’s first hit.

The challenge will be to identify who does not need that second dose, he and others have said.

“The implementation might not be that simple,” said Krammer, professor of microbiology at the Icahn School of Medicine at Mount Sinai in New York City.

Anyone who has been officially diagnosed with COVID-19 – not just people who felt bad for a few days and assumed they had it – or people who have antibodies to the virus that causes COVID-19 could likely skip a second shot.

As of last spring, antibody tests weren’t always reliable, Krammer said, but those still on the market are now good, though it’s still unclear whether a particular level of antibody should be. protected.

Antibody tests, also called serological tests, detect proteins produced by the immune system in response to an infection.

According to Krammer’s study, published earlier this month but not yet peer-reviewed, a previously infected person who receives their first vaccine has an immune response similar to that of a person who has not had COVID-19 by getting his second. They even have the side effects of a second shot with their first shot.

And that second hit adds little extra protection, according to the study.

“Changing the policy to only give these people a single dose of vaccine would not negatively impact their antibody titers, save them unnecessary pain and release many urgently needed doses of vaccine,” he concluded.

Dr Francis Collins, director of the National Institutes of Health, wrote about the study in his weekly blog.

“While much more research is needed – and I’m certainly not suggesting a change in current recommendations at this time – the findings raise the possibility that one dose may be enough for someone who has been infected with SARS-CoV. -2 and which has already generated antibodies against the virus, ”Collins wrote.

“But any serious consideration of this option will require more data. It will also be up to expert advisers from the FDA and the Centers for Disease Control and Prevention (CDC) to decide,” he added.

It is not clear how much more data or what kind of information would be enough to convince regulators.

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Another of the new studies, a pre-print from the University of Maryland, showed that 41 healthcare workers who recovered from COVID-19 had more antibodies after their first vaccine than 69 of their peers who did. had not caught the virus after their second.

And a pre-print from the Fred Hutchinson Cancer Research Center in Seattle found that the blood of people who have recovered from COVID-19 was not as effective in neutralizing the original virus or the variant that originated in South Africa. than the blood of people who had recovered and had been vaccinated. . Three other studies had similar results.

Each of the six studies released publicly this month tackles the issue in a different way, but “they all show basically the same thing,” Krammer said, “they confirm each other.”

Contact Karen Weintraub at [email protected].

Patient health and safety coverage at USA TODAY is made possible in part by a grant from the Masimo Foundation for Ethics, Innovation and Competition in Healthcare. The Masimo Foundation does not provide any editorial contribution.

© Damian Dovarganes / AP
Los Angeles health workers administer COVID-19 vaccines on February 24.

This article originally appeared on USA TODAY: People who have had COVID-19 may only need to be vaccinated once, studies show