(AP) – Two new studies provide encouraging evidence that having COVID-19 may offer some protection against future infections. The researchers found that people who made antibodies against coronavirus were much less likely to test positive again for up to six months and maybe more.
The results are auspicious for vaccines, which cause the immune system to produce antibodies, substances that adhere to a virus and help eliminate it.
The researchers found that people with antibodies derived from natural infections had “a much lower risk … of the order of the same kind of protection you would get from an effective vaccine” of getting the virus again, the Dr. of the U.S. National Cancer Institute.
“It’s very, very rare” to get infected again, he said.
The institute’s study had nothing to do with cancer: Many federal researchers have switched to coronavirus work because of the pandemic.
Both studies used two types of tests. One is a blood test for antibodies, which can persist for many months after infection. The other type of test uses nasal or other samples to detect the virus itself or pieces of it, suggesting a current or recent infection.
A study, published Wednesday by the New England Journal of Medicine, involved more than 12,500 healthcare workers at Oxford University hospitals in the UK. Of the 1,265 who had antibodies to the coronavirus at first, only two had positive test results for active infection in the next six months and neither developed symptoms.
This contrasts with the 11,364 workers who initially had no antibodies; 223 of them tested positive for infection in the following six months.
The National Cancer Institute study involved more than 3 million people who took antibody tests from two private labs in the United States. Only 0.3% of those who had antibodies initially tested positive for coronavirus, compared with 3% of those who did not have antibodies.
“It’s very gratifying” to see that Oxford researchers saw the same risk reduction, 10 times less likely to have a second infection if there were antibodies, Sharpless said.
His institute’s report was published on a website that scientists use to share research and is under review in a major medical journal.
The findings “aren’t a surprise … but it’s really reassuring because it tells people that immunity to the virus is common,” said Joshua Wolf, an infectious disease specialist at St. John’s Children’s Research Hospital. Jude of Memphis who had no role in either. to study.
The antibodies themselves may not provide protection, but they can only be a sign that other parts of the immune system, such as T cells, are able to fight off any new exposure to the virus, he said.
“We don’t know the duration of that immunity,” Wolf added. Cases of people receiving COVID-19 more than once have been confirmed, so that “people still need to protect themselves and others by avoiding reinfection.”
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