DNA provides new clues as to why COVID-19 hits people differently

DNA provides new clues as to why COVID-19 hits people differently

Since the beginning of the pandemic, the mercurial nature of the coronavirus has been highlighted. Some people get mild cold-like illnesses or even show no symptoms when infected, while others become seriously ill and may die from COVID-19.

What determines this fate is complicated and somewhat mysterious. Researchers are studying a wide variety of factors that may play a role, ranging from demographics and pre-existing conditions to vaccination status and even genetic clues.

Researchers know that older people are more likely to have serious complications from the disease. Unvaccinated people also have an increased risk of hospitalization and death compared to people who have received their COVID vaccines.

Unvaccinated people ages 50 and older were 12 times more likely to die from COVID-19 than vaccinated people who had received two or more booster shots, according to August data from the state Centers for Disease Control and Prevention. -United. For example, among the unvaccinated, there were 5.46 deaths per 100,000 people on August 28, compared to 0.49 per 100,000 for those who received more than two boosters.

Even among vaxxers, the number of hits matters. That same month, people 50 and older who received their first two vaccines and just one booster were nearly three times more likely to die (1.27 deaths per 100,000) than their peers who received two or more booster shots. .

Pre-existing health conditions

A litany of health conditions, including heart disease, kidney disease, chronic obstructive pulmonary disease (COPD), diabetes and obesity, increase the risk of poor COVID-19 outcomes at any age. However, some types of asthma may protect against the disease (SN: 02/05/22).

Cancer patients are among the most vulnerable to COVID-19. But even among cancer patients, some people are more vulnerable than others.

Cancer patients who are immunocompromised, either due to problems with their immune system or because they are taking immunosuppressive drugs, are more likely to contract severe COVID-19, die or develop a cytokine storm – a whirlwind of products immune chemicals that can trigger tissue- and organ-damaging inflammation, researchers report Nov. 3 in JAMA Oncology. The effect was worse for immunocompromised people who received cancer immunotherapy, compared to people who received other chemotherapy or no treatment.

This means that cancer patients with weakened immune systems “should be very careful and adopt strict measures to prevent them from catching COVID-19”, says study co-author Chris Labaki, cancer researcher at the Dana-Farber Cancer Institute in Boston.

“Wear masks as much as possible, clean everything, including washing your hands. Maybe don’t go to crowded public places where the risk of catching COVID-19 might be higher. People who have cancer patients in their lives may also want to be more careful to avoid the coronavirus, he says.

Genetic clues

But young and otherwise healthy people can get very sick, be hospitalized or even die from COVID-19 too. It’s hard to predict who might succumb, but researchers are looking for genetic clues.

Some studies have shown that versions of genes inherited from Neanderthals may protect against COVID-19, while other genetic inheritances passed down from Neanderthals may increase the risk of severe disease (SN: 02/17/21; SN: 02/10/20).

A massive international study examining the DNA of more than 28,000 COVID-19 patients and nearly 600,000 people who had not been infected (to the best of their knowledge) has confirmed that Neanderthal heritage is involved in the susceptibility to COVID-19.

The study also confirmed an earlier finding that people with type O blood may have some protection against coronavirus infection (SN: 08/07/21). What exactly explains the protection is still not known.

People with rare variants of a gene called toll-like receptor 7, or TLR7are 5.3 times more likely to get severe COVID-19 than those without the variants, the team also reported Nov. 3 at PLOS genetics. Biologically, the link makes sense. TLR7The protein is involved in signaling the immune system that a virus has invaded. Part of its job is to bring together interferons, immune system chemicals that are among the first responders to viral infections (SN: 08/06/20). Interferons alert cells to increase their antiviral defenses and help kill infected cells.

A gene called TYK2 is involved in the production of certain interferons. Genetic variants of this gene increase the risk of developing lupus but may protect against coronavirus infection, researchers report in a separate study also published November 3 in PLOS genetics. While the excitement of interferons can fend off the coronavirus, when there is no virus to fight, the immune system can damage the body with friendly fire, producing lupus or other autoimmune diseases. Such genetic compromises are common (SN: 10/19/22).

Evidence links many other genes to COVID-19 outcomes, according to several large studies. Some of these findings may hint at drugs that might better treat the disease.

Individual risk

But the problem with all these studies is that they can’t tell anyone what their chances are of having a bad outcome from catching COVID-19. For example, DNA testing company 23andMe told me that I had less than 2% Neanderthal DNA (SN: 05/22/18). I don’t know if this includes the variants that would make me more susceptible to serious illness or those that protect me from infection. What if I had both? And how does that play into my blood type and all the other genetic variants I may carry?

Then, you have to take into account your age, your health, your environment. Let’s face it, the latter is probably the most important. For example, if you have a job that exposes you to multiple people, you are at a higher risk of contracting COVID-19 than someone who works from home.

There’s nothing you can do about the genetic hand being dealt to you (at least not until genetic editing is perfected). Many experts I talk to say that improving indoor air in public buildings is what is really needed to avoid infections. It’s also out of most people’s hands. But there are still things you can do to reduce your risk. Labaki’s advice for cancer patients — mask up, avoid crowds, wash your hands — and stay up to date on vaccinations is good for everyone.

#DNA #clues #COVID19 #hits #people #differently

Leave a Comment

Your email address will not be published. Required fields are marked *