Studies begin to reveal why some people catch COVID-19 when others don't

Posted at 10:35 AM, Feb 06, 2022

(WXYZ) — Since the beginning of the pandemic, one question has perplexed the scientific community: Why do some people get infected with COVID-19, while others do not?

We’re starting to unravel the mystery. Studies have uncovered plausible reasons as to why some people do not get infected even after they’ve been exposed to the coronavirus. There are two very interesting ones I’d like to talk about.

The first one was published last month by Imperial College London. That study looked at families living together in the same household. Researchers found that family members who had high levels of T-cells from previous cold infections were less likely to get infected with the virus.

So why might that happen? Well, one reason is that T-cells are produced by your immune system, and one of their jobs is to prevent you from getting the same cold again. And while SARS-CoV-2 is different than the common cold, these T-cells could be recognizing it and providing cross-protection.

Now, the other research I’d like to mention analyzes how genetics play a role. A group of researchers from Imperial College looked at genes called human leukocyte antigen - or HLA for short. And they found that these genes could determine how a person would respond to the coronavirus. Most likely because HLA’s control a person’s immune response. Interestingly, the researchers found that participants who had a specific gene — HLA-DRB1*1302 – were a lot more likely to develop an infection with symptoms.

Our vaccines are definitely helping people avoid infection. Now omicron has certainly impacted our vaccines, but when you’re fully vaccinated and boosted, many people have a high level of protection. And many avoid getting infected. Not to mention, we know that our vaccines reduce not only severe infections but also hospitalizations and deaths as well.

I have always advocated for vaccines because research has shown that overall, they’re safe and effective. I would not encourage people to try and catch a cold in hopes of avoiding an omicron infection. While this new research is shedding light on why some people don’t get sick, it’s not guaranteed as a way to protect yourself. The best way to protect yourself and your loved ones is to get fully vaccinated and boosted.

Additional Coronavirus information and resources:

View a global coronavirus tracker with data from Johns Hopkins University.

See complete coverage on our Coronavirus Continuing Coverage page.