Had Covid but never felt sick? Scientists think they’ve finally cracked the secret of the ‘super-dodgers’

Scientists think they’ve found the secret of how some people who tested positive for Covid never got sick. 

And it all lies in their genes.

Experts found so-called Covid ‘super-dodgers’ have mutations in their immune system which allows their body to recognise the virus as being like a cold.

This allowed them to flush Covid out of their system early before it could run rampant and cause them to fall ill, in contrast to people without the mutated gene.

In an analysis of genetic data from about 1,500 people scientists found people with the quirk were eight times less likely to fall ill with Covid. 

Tested positive for Covid but never got sick? You could have mutation allowing you fight off the virus before it makes you ill (stock photo)

Only about one in 10 people within the general population are believed to have the genes offering them this form of protection. 

The mutations in question alter how human leukocyte antigen (HLA), a protein marker that flags up threats to the body’s immune system for disposal, works. 

This altered protein was able to recognise Covid as a threat early and summon the immune system to attack, increasing the odds of beating it before it even started to make them sick and start to have symptoms of the infection.  

In comparison, normal people’s immune system had to learn how to spot the virus from scratch, by which time it was already spreading inside them and making them ill. 

Professor Jill Hollenbach, an epidemiologist from the University of California and lead researcher in the new study, said the mutation gave some people a huge advantage against Covid, 

‘If you have an army that’s able to recognise the enemy early, that’s a huge advantage,’ The Telegraph reported. 

‘It’s like having soldiers that 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 regardless of if they had symptoms or not. 

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 jabs, which help reduce the chances of people becoming sick with Covid, became widely available. 

Of the participants experts found 136 individuals who were asymptomatic, meaning they suffered no symptoms of virus, at least two weeks before and after testing positive. 

Analysis revealed people with the altered HLA protein were eight times more likely to avoid feeling sick with Covid, compared to those without the mutation.

Further work, this time led by Australian scientists has also unpicked why the altered HLA is better able to recognise Covid as a threat.

Professor Stephanie Gras, an expert in biochemistry from La Trobe University in Melbourne said the immune cells with the mutation homed in on a part of the Covid virus structure called the NQK-Q8 peptide.

She explained this is a part of the virus very similar in makeup to a structure called the NQK-A8 peptide carried by cold viruses and allowed the immune system to flag the virus as a threat.

Further analysis by La Trobe University, Melbourne, Australia, found that immune cells of people with the mutation responded to 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 only answer questions about the pandemic and how some people avoided becoming ill.

Professor Gras said it could also be used to potentially develop new treatments.   

‘By studying their immune response, this might enable us to identify new ways of promoting immune protection against Sars-CoV-2 that could be used in future development of vaccine or drugs,’ she said.