Even though the highly transmissible Omicron variant that swept across the world towards the end of 2021 continues to be the dominant strain, there are people who have not tested positive throughout the whole pandemic.
Scientists are now looking to study this small demographic to see if their genes might help future treatment – or even prevent Covid infection altogether.
András Spaan, a clinical microbiologist from the Rockefeller University in New York, is leading the hunt into what might cause this Covid resistance, with a particularly focus on their genetic material.
He told the Washington Post: “What we are looking for is potentially very rare genetics variants with a very big impact on the individual.”
He is leading the international study, which already has 700 participants. Scientists are also screening more than 5,000 additional people who believe they could be immune to the virus.
Health workers, who went without face masks during the height of the pandemic and still managed to test negative for Covid on a weekly basis, are among those who are being examined for signs of immunity.
So how many people still haven’t caught Covid?
Journalist John Burn-Murdoch released a graph for the Financial Times last week explaining that – based on data from the Office of National Statistics (ONS) – nine out of 10 people in England have tested positive for Covid at some point in the pandemic.
Positive cases are falling at the moment, but the number of infections has fluctuated throughout the pandemic, according to which variant is spreading around and how up-to-date the general population is with its vaccination.
Still, even as some people have reported catching Covid multiple times, there is still a category who believe they have not caught the virus at all.
The US Centres for Disease Control and Prevention believes that six in 10 people across the States have had Covid at some point, at least once.
According to data website Staista.com, there have been almost 514 million Covid cases as of May 1, 2022 – which certainly makes the people who have avoided it an anomaly.
What could make some people Covid immune?
Experts speculate that some people just might have fewer receptors in their noses, throats and lungs meaning the virus finds it harder to bind to their bodies.
Alternatively, this minority could have previously been exposed to a similar virus which gave their immune systems a leg-up against Covid.
They may have also been born with a particular immune system already equipped to fight the virus, making it a genetic issue.
If scientists are able to find out why this small category of people have not been infected, both public health advice and Covid drugs could be significantly improved. It might even help protect the general population against future strains of the virus, which are expected.
However, individual use of masks, vaccines, and social distancing might affect the study’s ability to find those who are immune.
Frequent testers, those who wear masks indoors and avoid high-risk gatherings or travel obviously decreased their risk of catching the virus through their decisions. This means it was not so much to do with their genetics or immune system, but their approach to the pandemic.
Bob Wachter, professor and chair of the department of medicine at the University of California at San Francisco, also told the Washington Post: “It’s got to be a combination of caution, circumstance and luck.”