Scientists think they’ve found the secret to how some people who tested positive for Covid never got sick.
And it’s all in their genes.
Experts found that so-called ‘super evaders’ of Covid have mutations in their immune systems that allow their bodies to recognize the virus as a common cold.
This allowed them to flush Covid out of their system early before it could run rampant and cause them to get sick, unlike people without the mutated gene.
In an analysis of genetic data from about 1,500 people, scientists found that people with the idiosyncrasy were eight times less likely to get sick with Covid.
Tested positive for Covid but never got sick? You could have a mutation that allows you to fight off the virus before it makes you sick (stock photo)
It is believed that only about one in ten people in the general population have the genes that give them this form of protection.
The mutations in question alter the action of human leukocyte antigen (HLA), a protein marker that signals threats to the body’s immune system for removal.
This altered protein was able to recognize Covid as a threat early on and summon the immune system to attack, increasing the chances of beating it before it even started making them sick and showing symptoms of the infection.
By comparison, normal people’s immune systems had to learn how to recognize the virus from the start, by which time it was already spreading inside them and making them sick.
Professor Jill Hollenbach, a University of California epidemiologist and lead researcher in the new study, said the mutation gave some people a huge advantage against Covid,
“Having an army that can spot the enemy early is a huge advantage” The Telegraph reported.
“It’s like having soldiers who are prepared for battle and already know what to look for, and that these are the bad guys.”
In the study, the researchers used data from the US Covid-19 Citizen Science Study and the US Bone Marrow Registry to find people who tested positive for Covid, whether or not they had symptoms.
The analysis found 1,428 people who tested positive between February 2020 and the end of April 2021.
Scientists used this period as it was before Covid shots, which reduce the chances of people getting sick from Covid, became widely available.
Of the participants, experts found 136 individuals to be asymptomatic, meaning they had no symptoms of the virus at least two weeks before and after testing positive.
Analysis revealed that people with the altered HLA protein were eight times more likely not to feel sick with Covid, compared to people without the mutation.
Further work, this time led by Australian scientists, has also unraveled why the modified HLA is better able to recognize Covid as a threat.
Professor Stephanie Gras, an expert in biochemistry from Melbourne’s La Trobe University, said the immune cells carrying the mutation lodged in part of the Covid virus structure, the NQK-Q8 peptide.
She explained that this is part of the virus that is very similar in composition to a structure called the NQK-A8 peptide that is carried by cold viruses and allows the immune system to flag the virus as a threat.
Further analysis by La Trobe University, Melbourne, Australia, showed that immune cells from people with the mutation responded to a part of the Covid-19 called the NQK-Q8 peptide – which is very similar to the NQK-A8 peptide carried by cold viruses.
The research, published in the journal Nature, doesn’t just answer questions about the pandemic and how some people avoided getting sick.
Professor Gras said it could also be used to potentially develop new treatments.
“By studying their immune response, we may be able to find new ways to promote immune protection against Sars-CoV-2 that can be used in future vaccine or drug development,” she said.