Reinfection and COVID-19

reinfection Covid

Reinfection and COVID-19 “We still don’t understand a lot”: doctors warned coronavirus patients about the risk of reinfection.

Even people who have already had coronavirus should not relax due to the risk of reinfection, doctors and researchers warned. They note that there are reports of reinfections, but very few of them inspire optimism.

Those who have had the coronavirus should not think they cannot get infected again, writes The Wall Street Journal, citing the opinions of several doctors, scientists and health experts. So far, none of the experts knows for sure how long immunity from this infection lasts, the newspaper notes.

The answer to this question is essential for the development of vaccines and the choice of health authorities’ working methods. Doctors are now warning patients to stay socially distant and wear masks even after they have recovered from the coronavirus or tested positive for antibodies. “We still need to treat this virus with respect,” said infectious disease specialist Daniel Griffin.

Griffin and others emphasize that people quite often lose their immunity to certain viruses over time. In particular, this is characteristic of immunity to coronaviruses that cause the common cold. One recently published study of 191 people from New York showed that contracting one of two common cold-causing coronaviruses does not reduce the likelihood of reinfection with the same after 34 weeks. 

When a person becomes infected with a new coronavirus or other pathogens, his body gives an immune response: it produces antibodies and proteins that later help neutralize the virus. According to the lead author of the New York study, Martha Galanti, short-lived immunity to COVID-19 may be associated with a decrease in the number of pathogen-specific antibodies in the human body.

According to Galanti, the problem can also be caused by a mutation of the virus, due to which the antibodies are trained to recognize the previous strain, will not recognize the new strain of the same virus.

Some studies have shown that after two to three months after recovery, some patients with coronavirus have decreased the number of antibodies, or these antibodies become undetectable. Clinicians are left wondering if patients are currently susceptible to reinfection. Scientists from King’s College London conducted a study involving 65 coronavirus patients. They found that within 94 days, the number of antibodies that neutralize the pathogen decreased markedly.

They also found that people with a milder form of the disease had fewer antibodies than seriously ill patients. Moreover, three months later, these antibodies became undetectable, the newspaper notes.

However, this does not prove that all those who have had a mild form of coronavirus will necessarily be re-infected. If necessary, the human immune system can quickly produce more antibodies and warn the co-author of the London study, Stuart Neil. The critical question is whether the amount of these antibodies is reduced to a level that cannot protect against infection, Neil stated.

Some doctors claim to have encountered several patients who contracted the coronavirus twice. For example, Washington DC doctor Clay Ackerley spoke of a 50-year-old man who first contracted the coronavirus in April, then tested negatively twice, suddenly fell ill again after contact with an infected family member mid-June. At the same time, the second time, the disease was more severe, and the man had to go to the hospital several times. Ackerley stressed that there is no evidence that long-term immunity can be expected after recovery. 

“There is still a lot we don’t understand about this virus and immunology,” Ackerly said.

While recovered patients need to be careful, the few reports of reinfection are encouraging, said Sara Fortune, head of the Department of Immunology and Infectious Diseases at Harvard. “When you think about how many millions of people worldwide have suffered this viral infection now, these reports of reinfection with this virus are still infrequent,” she said.