Even people who have recovered from COVID-19 are urged to get vaccinated to prevent reinfection, especially amid the threat of a highly contagious variable delta — and there is mounting evidence that the shots offer survivors additional protection against mutations. (Gerald Herbert, The Associated Press)
Washington – Even the people who have recovered from it COVID-19 They are urged to get vaccinated, especially since the delta variant is highly contagious — and a new study found that survivors who ignored this advice were twice as likely to become infected.
Friday’s report from the Centers for Disease Control and Prevention adds to mounting lab evidence that people who’ve had a single bout of COVID-19 get a significant increase in virus-fighting immune cells — and the bonus of broader protection against new mutations – when they are. to feed.
“If you’ve had COVID-19 before, please get vaccinated,” said CDC director Dr. Rochelle Walinsky. “Vaccination is the best way to protect yourself and others around you, especially as the most contagious delta strain is spreading across the country.”
According to a new Gallup poll, one of the top reasons Americans cite for not planning a vaccination is to think they are protected because they are already infected with COVID-19. From the outset, health authorities have urged survivors to live up to the promises of vaccination on a larger scale. While the shots aren’t perfect, they provide powerful protection against hospitalization and death, even from a delta mutant.
Scientists say that an infection generally protects survivors from being infected with at least an identical version of the virus, but blood tests have shown that protection against variants of concern has been reduced.
The CDC study provides some factual evidence.
Researchers studied Kentucky residents with a lab-confirmed coronavirus infection in 2020, the vast majority of whom were between October and December. They compared 246 people who were reinfected in May or June this year with 492 similar survivors who remained healthy. Survivors who were never vaccinated were more likely to be reinfected than those who were fully vaccinated, even though most had their first bout of COVID-19 just six to nine months ago.
The study’s lead author, Allison Kavanaugh, a CDC disease researcher working with that state’s Department of Health, said a different type of coronavirus caused the most illness in 2020, while the newer alpha version was common in Kentucky in May and June.
She said this suggests that the natural immunity to early infection is not as strong as the boost these people can get from vaccination as the virus develops.
There is still little information about reinfection with the newer delta variant. But US health officials point to early data from Britain that the risk of reinfection appears to be greater with delta than with the alpha variant that was common, once six months have passed since the previous infection.
“There is no doubt” that vaccinating a COVID-19 survivor improves both the quantity and breadth of immunity “so that it includes not only the parent (virus) but also its variants,” said Dr. Anthony Fauci, the chief infectious disease expert for the US government, said in a recent White House briefing.
The Centers for Disease Control and Prevention recommends a full vaccination, that is, two doses of vaccines, for everyone.
But in a separate study published Friday in the JAMA Network Open, Rush University researchers report that just one dose of a vaccine gives previously infected people a greater boost in virus-fighting immune cells, more than people never infected with two doses.
Other recent studies published in Science and Nature show that the combination of previous infection and vaccination also increases the strength of people’s immunity against an altered virus. This is what virologist Shane Crotty of the La Jolla Institute of Immunology in California calls “hybrid immunity.”
And vaccinated survivors “can make antibodies that can recognize all kinds of variants, even if you’ve never been exposed to the variant,” Crotty said. “It’s so sweet.”
A word of warning to anyone considering skipping a vaccination if they’ve had a previous infection: The amount of natural immunity can vary from person to person, possibly depending on how sick they are to begin with. The Rush University research found that 4 out of 29 previously infected people had no detectable antibodies before being vaccinated — and the vaccines worked just as well for them as they did for people who never had COVID-19.
Why do so many previously infected people react so strongly to vaccination? It has to do with how the immune system develops multiple layers of protection.
After a vaccination or infection, the body develops antibodies that can fight the coronavirus the next time it tries to invade. Of course they fade over time. When an infection creeps in, T cells help prevent serious disease by killing virus-infected cells — and memory B cells spring into action to produce many new antibodies.
These memory B cells don’t just make copies of the original antibodies. In immune system camps called germination centers, she also shunts antibody-producing genes to test a range of virus fighters, explains John Wehrey, an immunologist at the University of Pennsylvania.
The result is essentially a library of antibody prescriptions the body can choose from after future exposure — and this process is even stronger when vaccination activates the immune system’s original memory to fight off the virus itself.
With the superinfection of the delta variant, Crotty said, despite previous infection, vaccination is “more important now than before to be sure.” “The breadth and potency of your antibodies to the variants will be much better than what you have now.”
The Associated Press’s Department of Health and Science is supported by the Howard Hughes Medical Institute’s Division of Science Education. AP is solely responsible for all content.
Pictures
Related stories
More stories you might be interested in
–
–
