What is the secret of people who never get COVID? Are they immune? : ScienceAlert

It has been more than three years since the first known COVID-19 infection. Since then, we’ve seen hundreds of millions of cases around the world.

You’ve probably had it – at least once, if not several times – as has almost everyone you know. As the continuing waves of infections roll in, fewer and fewer people have never caught COVID-19.

But even taking into account those who already had it and didn’t realize it, there are probably still people out there who managed to avoid the virus completely (until now).

Last year I wrote about people who have not yet been infected. Were they somehow immune? Did they possess any advantageous genetic mutations? Were they simply avoiding people and continuing to take precautions? Or did they just get lucky and their time would inevitably come?

Unfortunately, we still don’t know why some people have managed to avoid COVID-19 for so long. Science takes time.

We saw research take place at unprecedented speed in 2020 to understand SARS-CoV-2 (the virus that causes COVID-19) and develop treatments and vaccines. But this level of funding and collaboration is difficult to sustain in a world with so many valuable areas of research.

That said, some research is looking in particular at whether a genetic element helps explain why certain people never get COVID-19. But while this research is important, we must not lose focus on those who suffer from the disease and its long-term effects.

Is immunity in the genes?

The COVID Human Genetic Effort, led by researchers in the US, recruited people with known exposure to the virus but who had not. This includes, for example, healthcare workers or people living in a household with a confirmed case of COVID-19.

Scientists will examine their DNA and look for unusual mutations that might explain an apparent resistance to SARS-CoV-2 infection. This could be a mutation in cell receptors or enzymes needed for the virus to enter our cells, or perhaps a mutation in a gene involved in the immune response to infection.

Studies that seek to discover anomalies in our DNA, called genome-wide association studies, have already managed to identify genetic mutations that make some people resistant to other infections, such as HIV and norovirus (the winter vomiting virus). If we can identify the reasons why people might be immune to a particular virus, then theoretically this knowledge could be used to prevent infection.

But is it really that simple? Despite our understanding of genetic mutations that protect a minority of people against norovirus, there is no vaccine or treatment for this virus. And the infamous “CRISPR babies” (several children born in 2018 whose genomes were edited in an attempt to make them immune to HIV), have received criticism for dubious ethics, not to mention their illegality.

It is possible that it is not a mutation in one gene, but a combination of mutations in several genes, that make a small number of people immune to COVID-19. Targeting multiple genes without causing unwanted side effects can be tricky and would make leveraging this knowledge for anti-COVID-19 drugs much more difficult.

But understanding the genetic mutations that make someone resistant to COVID-19 could provide valuable insights into how SARS-CoV-2 infects people and causes disease. In other words, it might be interesting scientifically, but maybe not clinically.

While it will take some time to get answers from these studies, scientists believe that there is a small group of people who are naturally immune to SARS-CoV-2 due to their genes.

Time to change focus?

As scientists, we can fixate on certain details of our research. It is always important to remember that there are people on the other side of these infectious diseases.

Although SARS-CoV-2 continues to infect people around the world and is constantly mutating and evolving into new variants, its overall severity has been greatly reduced thanks to effective vaccines.

At the same time, around two million people in the UK report long-term COVID, of whom nearly a fifth have symptoms so severe that the condition significantly limits their daily activities.

While there are some theories about what contributes to long-term COVID, including micro-clots in the blood and chronic inflammation, we don’t really know why some people are affected and others aren’t. So perhaps our focus should shift from the genetic determinants of immunity to SARS-CoV-2 to exploring whether some people might have a genetic predisposition to a potentially life-altering chronic disease.The conversation

Lindsay Broadbent, Professor of Virology, University of Surrey

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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