Scientists see signs of continued immunity to Covid-19, even after mild infections


Notably, several of the new studies have found these powerful responses in people who have not developed serious cases of Covid-19, added Drs. Iyer. Some researchers have worried that infections that take a smaller toll on the body are less memorable for the tough cells of the immune system, who may prefer to invest their resources in serious attacks. In some cases, the body itself could spread the viruses so quickly that it did not catalog them. “This article suggests that this is not true,” said Drs. Iyer. “You can still get lasting immunity without suffering the effects of infection.”

What has been observed in people who fight mild cases of Covid-19 may not be true for patients in the hospital, whose bodies struggle to march a balanced immune response to the virus, as those who were infected but none had symptoms. Research groups around the world are studying the full range of answers. But “the vast majority of cases are these mild infections,” said Jason Netland, an immunologist at the University of Washington and an author on the paper that checks at Nature. “If these people are going to be protected, that’s fine too.”

This new disk of studies could also address fears more about how and when the pandemic will end. On Friday, updated guidance released by the Centers for Disease Control and Prevention was misinterpreted by several news outlets suggesting immunity to the coronavirus may last only a few months. Experts responded quickly, notes the dangers of propagating such statements and points to the wealth of evidence that people who previously had the virus are likely to be protected from reinfection for at least three months, if not much longer.

In line with other recent reports, the new data reinforces the idea that, “Yes, you develop immunity to this virus, and good immunity against this virus,” said Dr. Eun-Hyung Lee, an immunologist at Emory University who was not involved in the studies. “That’s the message we want out.”

Some diseases, such as the flu, can plague populations several times. But this is at least partly attributed to the high mutation rates of influenza viruses, which can quickly make the pathogens unrecognizable to the immune system. Coronaviruses, on the other hand, tend to change their appearance less easily from year to year.

Still, much remains unknown. Although these studies indicate the potential for protective ability, they do not prove protection in action, said Cheong-Hee Chang, an immunologist at the University of Michigan who was not involved in the new studies. “It’s difficult to predict what will happen,” he said. Chang. ‘People are so heterogeneous. There are so many factors at play. “

Animal research could help fill a few gaps. Small studies have shown that one bolt of the coronavirus rhesus-macaques seems to protect against re-contracting.