Do you know someone who tested positive for COVID but never felt anything?Or that he says he never caught the virus, even when his spouse had health problems in bed.
Scientists estimate that more than 20% of other people infected with COVID have no symptoms, and some of them don’t even know they’ve become inflamed. Now, a new study published in Nature on July 19 indicates that their genetics may be just the explanation for why the virus didn’t make them sick.
Some other people have a version of a gene in their immune formula called HLA-B that protects them from the effects of the virus. The study found that other people with this special HLA-B variant are 2 to 8 and a portion times more likely to be asymptomatic than those without a variant.
Goats and Soda covered a first edition of this study last year. Since then, scientists have figured out how this genetically enhanced protection works: thanks to immune cells, infections of other seasonal coronaviruses, i. e. many colds, also know how to attack COVID-19.
Jill Hollenbach, an immunologist at the University of California, San Francisco who led the studies described in the new study, hasn’t had a mild experience with COVID.
“I had COVID. I was in poor health for about a week. I didn’t like it.
Hollenbach had a non-unusual kind of experience with COVID, moderate symptoms, and eventually a full recovery. But in her research, she says she’s not unusually interested in excessive cases.
“An excess is a very serious illness [resulting in hospitalization or death]. And the other end of that spectrum is that you had no symptoms. We don’t see what’s driving this,” she says.
The new discoveries are due, in part, to smart Samaritans who signed up to donate bone marrow as part of the Be The Match program. Some other people who had provided a DNA pattern to the program also signed up to participate in Hollenbach’s COVID-19 citizen science study.
“We simply asked other people who were registered donors to track their experience with COVID on a smartphone app and agreed to allow us to review their genetic knowledge and link it to their answers,” Hollenbach says.
Hollenbach’s idea is that the same HLA genes used to locate matches in bone marrow may also be linked to COVID outcomes. “There are more diseases and situations related to variation in the HLA genomic region than any other genomic region. And that’s it,” he says.
HLA is a set of genes involved in the immune formula found on the surface of our cells. When we become inflamed with a virus, HLAs will hold a part of that virus as a flag, telling the immune formula to kill the inflamed cell.
There are many other variants of HLA. Hollenbach discovered that one of them, HLA-B*15:01, was related to asymptomatic COVID.
“To be fair, not everyone who has [HLA-B* 3:01 p. m. ] will be asymptomatic,” Hollenbach says. But it was a clear, solid and repeatable combination. “
So how does this coverage work?
Research shows that other people with HLA-B*15:01 have improved coverage against COVID after being exposed to very similar bloodless viruses. This is the result of a procedure called cross-reactive immunity.
“The idea is that his exposure to certain seasonal bloodless viruses, which in some cases have many similarities to parts of SARS-CoV-2, gave him some existing immunity,” Hollenbach says.
This is in addition to the number of vaccines, adding the COVID vaccine, that work. If it displays the immune formula of a piece of virus, you can use it as a template to create “memory T cells. “
So when other people with HLA-B*15:01 are exposed to the common cold, they create COVID-like T cells. And this style gives them enough protection against the virus so that in case of infection, they have no symptoms.
Hollenbach and his team demonstrated this by using T-cell samples from other people with HLA-B*15:01 that were collected before the pandemic, and then exposing those mobiles to COVID. Lo and behold, T-mobiles can react to the COVID virus.
The clinical network is very happy with the new study.
“Well, it’s a breakthrough,” says Dr. Eric Topol, a physician and scientist at The Scripps Research Institute who was not involved in the study. “I think it may end up giving us a whole new map of what to do in terms of drugs and vaccines, which is extraordinary. “
Although Topol is very enthusiastic about this research, he has some concerns. “The main limitation is that [the study] has 3 cohorts that were almost all of European ancestry,” he says.
This type of limited ethnic basin is a woefully not unusual challenge in disease studies and means that these studies do not apply to giant teams of people.
The other major limitation of the study, Topol says, is that the symptoms were self-reported, meaning that other people who identified themselves as asymptomatic might have had a late-onset of symptoms or mild symptoms they didn’t record in the app.
And there is a caveat that this study does not completely solve the mystery of asymptomatic COVID infections. “The genetic disposition we discovered in this test is from some asymptomatic diseases, but not all,” Hollenbach says. “So, actually, there are other genetic and non-genetic aspects that are vital in asymptomatic infection. “
The article states that only one in five people in the study who reported having no COVID symptoms had the HLA-B variant*15:01.
Therefore, those lucky enough to be born with HLA-B*15:01 may have integrated ions opposed to COVID. There might even be other versions of HLA that other people do too.
And what does this research mean for those who don’t enjoy the advantages of mobile T memory protection?
“I think it gives us an opportunity to think about the prospective progression of vaccines and treatments that aim to prevent infection while also preventing symptoms,” Hollenbach says.
These kinds of advances in these studies are still a long way off, but they can lead to really extensive advances in treatment along the way.
“If you can find a way for other people not to have health problems because of COVID, it’s extraordinary,” Topol says.