Even people who have recovered from COVID-19 are encouraged to get vaccinated, especially as the number of highly contagious delta mutants increases. New studies show that survivors who ignore advice are more than twice as likely to be re-infected.
A Friday report from the Centers for Disease Control and Prevention shows that people who have suffered a single COVID-19 attack dramatically increase the number of immune cells that fight the virus and gain broader protection bonuses against the new mutants. Increased evidence of the play. Vaccination.
“Even if you’ve been infected with COVID-19 before, get vaccinated,” CDC director Dr. Rochelle Walensky said. “Vaccination is the best way to protect yourself and others around you, especially as more contagious delta variants are spreading across the country.”
One of the main reasons Americans don’t plan to vaccinate, according to a new Gallup study, is the belief that they are already infected with COVID-19 and are protected. From the start, health officials urged survivors to seek broader immunization pledges. The injections aren’t perfect, but they also offer strong protection against hospitalization and death from delta mutants.
Scientists say infections usually protect survivors from severe re-infections with at least similar versions of the virus, but blood tests show less protection against mutants of concern.
CDC research provides concrete evidence.
Researchers interviewed residents of Kentucky with a lab-confirmed coronavirus infection in 2020. The majority of them occurred between October and December. They compared 246 re-infected in May or June this year with 492 similar survivors who remained healthy. Unvaccinated survivors had a significantly higher risk of reinfection than fully vaccinated survivors, but most had their first COVID-19 attack only 6 to 9 months ago. Wakes up.
Another variant of the coronavirus caused most illness in 2020, but the new alpha version prevailed in May and June in Kentucky, according to the study’s lead author, the US Center for Disease Control and Prevention. . Alyson Cavanaugh, who works with the Department of Health, said.
This suggests that the innate immunity against previous infections is not as strong as the boost these people can get from the vaccination as the virus progresses.
Little information is yet available on reinfection with the new delta variant. However, U.S. health officials have said Delta appears to be at greater risk for reinfection than the once common alpha mutant six months after the previous infection, according to first UK data. I point out.
Vaccination of COVID-19 survivors “no doubt” improves both the amount and extent of immunity. This “will allow us to cover not only the original (virus) but also the variants,” Dr.Anthony Fauci, the US government’s leading infectious disease expert, said in a recent White House briefing. ..
The CDC recommends that everyone be fully vaccinated, that is, both be vaccinated twice.
However, in another study published Friday to the JAMA Network Open, researchers at Rush University found that a single dose of the vaccine dramatically increased the number of immune cells that fight and infect the previously infected virus. He reported that he could get it with two injections than someone who had never done before.
Other recent studies published in Science and Nature have shown that the combination of previous infections and vaccination also broadens people’s immunity to changing viruses. This is what virologist Shane Crotty of the Lahora Institute of Immunology in California calls “hybrid immunity”.
Vaccinated survivors “can make antibodies that can recognize all types of mutants, even if they have never been exposed to them,” Crotti said. “It’s pretty sweet.”
One of the warnings for those considering skipping vaccination if they have already been infected: The degree of innate immunity varies from person to person and likely depends on the severity of the initial illness. A Rush University study found that four of 29 people previously infected did not have detectable antibodies before vaccination. The vaccine worked the same as a person who had never received COVID-19.
Why do so many previously infected people respond so strongly 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 dodge the coronavirus the next time it tries to invade it. They naturally declined over time. If the infection passes through them, the T cells help prevent serious illness by killing the cells infected with the virus, and the memory B cells work to make many new antibodies.
These memory B cells do more than just make a copy of the original antibody. John Wellie, an immunologist at the University of Pennsylvania, explained that in an immune system boot camp called the germinal center, antibody-producing genes are mutated to test the range of these virus fighters.
The result is essentially a library of antibody recipes for the body to choose from after future exposure. The process becomes more powerful when the vaccination triggers the original memory of the immune system’s fight against the virus itself.
Due to the hyperinfectivity of the delta mutant, vaccination despite previous infections is “more important now than before to be certain,” Crotti said. “The extent of antibodies and their potency against mutants is much better than current antibodies.”
The Associated Press’s Department of Health Sciences is supported by the Howard Hughes Medical Institute’s Department of Science Education. AP is solely responsible for all content.
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