Researchers are trying to crack the code on why some people, despite being exposed to Covid-19 on a number of occasions, don’t contract the virus.
It comes as one woman had been exposed to the virus in a trial-setting and had the virus inserted into her nose, only to test negative.
Phoebe Garrett, a 22-year-old from High Wycombe, England, has knowingly been exposed to Covid-19 four times, including at a party where everyone else tested positive afterwards.
Last March, she took part in the world’s first Covid challenge trial. This saw participants having live virus dripped into the nose and pegging it shut for hours.
“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,” she said.
Garrett, along with a number of other participants, still resisted the virus after the tests.
“My mum has always said that our family never gets flu, and I’ve wondered if there’s maybe something behind that,” she told The Guardian.
16 of the 34 people who participated in the trial did not catch Covid-19. However, about half of them tested positive for low levels of the virus, several days after exposure.
Unfortunately, despite being exposed to the virus in her social life and in the trials, Garrett tested positive on routine lateral flow test in January. She developed mild symptoms and has since recovered.
Researchers are hoping that by understanding the immunity of some against Covid-19, they can create new treatments for the virus.
Some studies have found it possible to “shake off” the virus at the early stages of infection. It suggested that memory T-cells from previous coronavirus infections, such as those from common colds, “cross-related with the new coronavirus and protected them from Covid”, The Guardian reports.
Separate research carried out in Sweden is said to suggest that immune responses triggered by the H1N1 influenza or swine flu back in 2009/2010, may provide partial protection. This study has yet to be peer reviewed.
As well as that, some people, a small number of them, may even be genetically resistant to Covid-19. This is the case for other diseases, such as HIV, Malaria and norovirus.
That being said, Prof András Spaan at the Rockefeller University in New York said that it is unlikely that the majority of those who have avoided Covid-19 are genetically resistant, even if they have some partial immune protection. This would mean that there is no guarantee that they’ll never become infected, which Garrett learned the hard way.
