Researchers compared about 6,500 people with a long COVID diagnosis to nearly 1 million people without. People were 1.6 times more likely to develop long COVID if they had a variant in a gene called FOXP4. That same gene is also known to be a culprit in lung cancer and severe COVID.
MANY QUESTIONS REMAIN UNANSWERED
While these studies help explain the wide range of responses to the virus, many questions remain unanswered. For example, why were some people not just asymptomatically infected, but never infected?
Casanova is interested in, say, that “health care worker without a mask in 2020 that has repeatedly tested negative, negative, negative. They’re seemingly resistant to infection and we think there’s a genetic basis for that”. His lab is currently analysing some 2,000 genomes among that group to try to fish out the gene responsible.
Scientists would also like to understand if there are genes involved in other, rarer situations, like the people whose infections cause brain swelling, or others that get a form of heart inflammation called myocarditis after getting the mRNA vaccines.
Like all science, understanding the genetic link to susceptibility is just pulling on the first thread. So much other work needs to be done to unravel the rest. Hollenbach’s findings about asymptomatic COVID-19, for example, should prompt more exploration into alternate approaches to vaccination.
The existing vaccines all try to prevent infection altogether, but there could be merit in focusing on vaccines designed to take advantage of that memory T-cell response that seems to work so well for people with the right genetics. “Maybe you get infected, but manage it so quickly and effectively that you don’t experience illness”, she says.
It is important to keep unravelling these mysteries. They teach us better ways to address this virus, which we know is here to stay, and also contribute to the broader understanding of how genes shape the immune response.
Source: CNA
