Scientists Try to Solve Mystery of Why Some Individuals Don’t Get COVID-19

16:56 GMT, 3 March 2022
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Max Gorbachev
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Researchers say cracking this puzzle will be an ultimate game-changer for the pandemic and will end it, as identifying mechanisms that prevent infection could lead to the development of drugs that not only protect people from getting the disease, but also prevent them from passing COVID-19 on to others.
Sputnik
Can one maintain social distancing, wear masks, use sanitiser, avoid public events, and still get COVID-19, while others do not follow safety rules, attend large events, hug and kiss people, and then all the same not get the disease? How is this possible? Scientists around the world are trying to solve this mystery.

One potential reason is that some people could be genetically resistant to COVID-19. Such resistance has been displayed in individuals to different diseases, such as malaria or HIV. Professor András Spaan at the Rockefeller University in New York believes that those who are resistant to COVID-19 do not have the receptor used by the coronavirus pathogen to enter cells.

Professor Spaan says it is unlikely that that the majority of those who avoided getting infected with the disease are genetically resistant, rather they have some partial immune protection. This was the case with Phoebe Garrett from England. The 22-year-old participated in trials last year, which saw researchers trying to infect people with COVID-19. Among other things, individuals dripped the live virus into their noses and pegged their nostrils shut for several hours. Phoebe didn’t catch the disease.

"We had multiple rounds of tests, and different methods of testing: throat swabs, nose swabs, other types of swabs that I’d never done before like nasal wicks – where you hold a swab in your nose for a minute – as well as blood tests, but I never developed symptoms, never tested positive. My mum has always said that our family never gets flu, and I’ve wondered if there’s maybe something behind that", the 22-year-old said.

However, in January, the young woman was infected with Omicron, a strain of COVID-19 that doctors say is more infectious than other variants and is capable of evading vaccines.
During the trials, Garrett was not the only person who didn't get the coronavirus. Of the 34 who were exposed to the virus, 16 failed to develop an infection, although half of the participants transiently tested for low levels of COVID-19.

According to Professor Christopher Chiu at Imperial College London, who led the study, this can be explained with the immune system of those individuals quickly shutting down embryonic infection.

"In our previous studies with other viruses, we have seen early immune responses in the nose that are associated with resisting infection. Together, these findings imply that there is a struggle between the virus and host, which in our 'uninfected' participants results in prevention of infection taking off", said Professor Christopher Chiu.

Still another possible reason why some individuals are resistant to COVID-19 is that their bodies can shake off the disease before it establishes a permanent presence in body. Dr Leo Swadling at University College London monitored a group of doctors who were regularly exposed to COVID-19 patients, but never tested positive or developed antibodies.

Blood tests revealed that around 15 percent of healthcare workers had T-cells that react against the disease, plus other markers of viral infection.
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