Vaccinated survivors can produce antibodies that can recognize all kinds of variants, even if you have never been exposed to the variant.
Pat Moore, Chester County Health Department, Pennsylvania, fills a syringe with Modern COVID-19 vaccine before giving it to emergency medical workers and health care personnel at the Chester County Government Services Center, on Tuesday, December. February 29, 2020, in West Chester, Pennsylvania. Image Credit: AP Photo / Matt Slocum
Even people who have recovered from COVID-19 Vaccination is urged, especially as the extra-contagious delta variant increases, and a new study shows that survivors who ignored that advice were more than twice as likely to be re-infected.
Friday’s report from the Centers for Disease Control and Prevention adds to mounting laboratory evidence that people who had an episode of COVID-19 They get a dramatic boost in virus-fighting immune cells, and an added bonus of broader protection against new mutants, when vaccinated.
“If you have had COVID-19 first, please get vaccinated, ”said CDC Director Dr. Rochelle Walensky. “Getting the vaccine is the best way to protect yourself and others, especially as the more contagious delta variant spreads across the country.”
According to a new Gallup poll, one of the top reasons Americans cite for not planning to get vaccinated is the belief that they are protected because they already had COVID-19 . From the beginning, health authorities have urged survivors to obtain vaccination promises for the broadest protection. While the shots aren’t perfect, they provide strong protection against hospitalization and even death from the delta mutant.
Scientists say the infection generally leaves survivors protected against severe reinfection with at least a similar version of the virus, but blood tests have indicated that protection against worrisome variants is diminished.
Researchers studied Kentucky residents with a confirmed lab coronavirus infection in 2020, the vast majority between October and December. They compared 246 people who were reinfected in May or June of this year with 492 similar survivors who remained healthy. Survivors who were never vaccinated had a significantly higher risk of reinfection than those who were fully vaccinated, although most had their first episode of COVID-19 just six or nine months ago.
A different variant of the coronavirus caused the most illnesses in 2020, while the most recent alpha version was predominant in Kentucky in May and June, said study lead author Alyson Cavanaugh, a CDC disease detective who works with the U.S. Department of Health. that state.
That suggests that the natural immunity from a previous infection is not as strong as the boost such people can get from vaccination as the virus evolves, he said.
There is still little information on reinfections with the newer delta variant. But US health officials point to early data from Britain that the risk of reinfection appears higher with delta than with the once-common alpha variant, once people have passed six months of their previous infection. .
There is “no question” that vaccinating a COVID-19 The survivor enhances both the amount and the breadth of immunity “to cover not only the original (virus) but also the variants,” said Dr. Anthony Fauci, the US government’s leading infectious disease expert, in a Recent briefing at the White House.
The CDC recommends full vaccination, that is, both doses of two-dose vaccines, for everyone.
But in a separate study published Friday in Open JAMA networkResearchers at Rush University reported that just one dose of vaccine gives those previously infected a dramatic increase in immune cells that fight viruses, more than people who have never been infected receive with two injections.
Other recent studies published in Science other Nature Show that the combination of a previous infection and vaccination also increases the strength of people’s immunity against a changing virus. It’s what virologist Shane Crotty of the La Jolla Institute for Immunology in California calls “hybrid immunity.”
Vaccinated survivors “can produce antibodies that can recognize all kinds of variants, even if you have never been exposed to the variant,” Crotty said. “It’s pretty sweet.”
A word of caution for anyone thinking of skipping vaccination if they had a previous infection: the amount of natural immunity can vary from person to person, possibly depending on how sick they were at first. The Rush University study found that four of the 29 previously infected people had no detectable antibodies before they were vaccinated, and the vaccines worked for them as they do for people who had never before. COVID-19 .
Why do many of the previously infected people have such a robust response to vaccination? It has to do with how the immune system develops multiple layers of protection.
After vaccination or infection, the body develops antibodies that can defend itself coronavirus next time I try to invade. Those naturally decrease over time. If an infection escapes them, T cells help prevent serious illness by killing virus-infected cells, and memory B cells jump into action to produce many new antibodies.
Those memory B cells don’t just make copies of the original antibodies. In immune system training grounds called germ centers, they also mutate antibody-producing genes to test for a variety of those virus fighters, explained University of Pennsylvania immunologist John Wherry.
The result is essentially a library of antibody recipes that the body can choose from after future exposures, and that process is strongest when the vaccine activates the immune system’s original memory of fighting the real virus.
With the super infectivity of the delta variant, getting vaccinated despite a previous infection “is more important now than before, hands down,” Crotty said. “The amplitude of his antibodies and the potency against the variants will be much better than what he has now.”