Is there a reason why some get COVID-19, others don’t?

Researchers studying genetic, physiological factors

BOSTON — Think COVID-19 has had a major impact on your life? It’s probably nothing compared to what Dr. Robi Tamargo has gone through. To date, the Jacksonville, FL clinical psychologist has been infected four times with the virus.

“Well, the first time I got it was May 7th, 2020,” she said. “The first day I awakened with all the typical symptoms.”

But that first bout turned out to be anything but typical. As the day progressed, Tamargo said half her face went numb. At the hospital, doctors discovered a blood clot in her right cerebral artery.

“It came in with a roar, and it just hasn’t left me,” she said.

Tamargo’s subsequent bouts included two with the Delta variant in the fall of 2021 — and then a hard hit by Omicron earlier this year.

“I got profoundly sick,” Tamargo said. “And I was sick for 11 days.”

And it wasn’t that Tamargo was a constitutionally ‘sick’ person. Just the opposite, in fact.

“I was incredibly physically fit,” she said. “I worked out every morning at my local Orange Theory fitness. I’ve been an athlete my entire my life. I was all-American in two sports at University.”

And thus remains one of the great mysteries of Covid-19: Why some people seem more prone to infections than others.

“We still have an awful lot to learn about COVID and the peculiarities of this virus and its interaction with the human immune system,” said William Schaffner, MD, an infectious disease specialist at Vanderbilt University Medical Center.

One theory as to COVID’s seeming capriciousness is that not everyone is built to resist the virus the same.

“You know some things are still beyond our scientific information,” Schaffner said. “There are studies underway to try to determine whether people have genetic predispositions to getting this, that or another kind of infection. So, spouses — living together, sleeping together, eating together — could one be more susceptible than the other?”

Another area for exploration — why children have pretty continuously been more resistant to infection and serious COVID illness.

One hypothesis: the receptor the virus needs to bind to in order to infect cells is underdeveloped in kids.

“So the virus may hit the child but can’t attach,” Schaffner said. “And if the virus can’t attach, it can’t make you sick.”

Of course, there are likely many who think they’ve never been infected with COVID, but probably were at some point in the pandemic.

“COVID, although it can infect you, may not cause any symptoms at all,” Schaffner said. But that infection, mild as it might be, does confer some protection over subsequent infections — which tend, anyway, to be milder than the first infection.

But back to Robi Tamargo... who just about a month ago, got over that very rough fourth infection. Does she think the pandemic is over — and with it, the danger she might contract COVID a fifth time?

“I don’t think the danger is over for anyone,” she said. “And in fact, I just was told yesterday, a friend told me, that their 42-year-old cousin just died here in Florida the day before yesterday. A super-fit woman who got COVID and died. So this is not over.”

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