Factors in our favor as we face possibility of winter COVID surge

October 28, 2021
National Institute of Allergy and Infectious Diseases illustration of coronavirus.
Illustration of the coronavirus by the National Institute of Allergy and Infectious Diseases.

It’s hard to think about the possibility of another winter COVID surge when our numbers are falling like they are. Cases in the Tri-county area dropped another 16% over the past week. But we need to be prepared, said Michael Sweat, Ph.D., the leader of the Medical University of South Carolina’s COVID tracking team.

“Watching what's happening in Europe has got me concerned. Very high growth rates are happening throughout a large part of Europe. The U.K. in the past few weeks went up 21%, Ireland 50%, the Netherlands up 115%, Denmark up 111%,” Sweat said.

Those are places with high vaccination rates that saw cases plunge, just like ours are doing right now. But cases in much of Europe recently began to rise again. The World Health Organization blamed uneven vaccination rates. Other issues may include mask fatigue, large indoor gatherings and waning immunity from vaccines.

Will the same thing happen here? Maybe, but we have three key factors in our favor, Sweat said.

“One of them is vaccination. We are slowly getting more people vaccinated. Soon, younger children are going to be eligible for vaccinations, so that again could help put the brakes on transmission.”

Dr. Michael Sweat 
Dr. Michael Sweat

But Sweat noted parental resistance could affect that. “I've seen surveys that suggest that a lot of parents want to wait and see before deciding whether to get their child vaccinated.”

Right now, about 55% of people eligible to get the vaccine in South Carolina, 12 and older, are fully vaccinated. That percentage is slowing ticking up. Some people also qualify for booster shots, which could reduce their risk of getting a breakthrough infection.

“The second factor that could help us this winter is natural immunity,” Sweat said. “We just had a big wave of COVID. Over 45% of all of our cases happened in the past seven months. And many of them happened in the past couple of months. That will slow things down.”

Sweat said that while just 16% of people in the Tri-county area have tested positive for COVID and were entered into the statewide statistics since the start of the pandemic, the number is likely much higher – and so is the level of natural immunity.

“The reality is that there are many, many other people who have gotten infections and didn't get tested. And the CDC has pretty strong data indicating for every one case detected, about 4.2 other people have gotten infected but those infections didn't get captured. So if you take that into account, it would suggest up to 68% of the population would have likely had some kind of infection.”

But it’s unclear how long natural immunity lasts. One recent study focusing on the genome of the coronavirus suggested people could be reinfected between three months and five years after the initial infection.

Sweat’s third factor in our favor is a new antiviral drug called molnupiravir made by Merck. “It's anticipated among many that it's going to be approved right away and available in December. This drug in clinical trials was incredible. It reduced the risk of hospitalization and death in newly diagnosed high-risk patients by 50%,” Sweat said.

“It could also reduce transmission of COVID because it disrupts the replication of the virus. It's a real breakthrough.”

Sweat, a professor in the College of Medicine at MUSC who is also affiliated with the Johns Hopkins Bloomberg School of Public Health and served as research scientist with the Centers for Disease Control and Prevention, said we could know in the next few weeks what is likely to happen here this winter.

“I'd look at what's happening in the cold regions of our country. Is it following the same pattern as last year? Vermont, which has one of the highest vaccination rates in the country, is having increases in their COVID case rates. And there seems to be a little bit of an outbreak happening up in New England – Massachusetts is starting to signal increases.”

If our numbers do start to go up, Sweat said the best way to slow an increase is to clamp down quickly. “The science strongly shows that if you can do mitigation, you want to do it in the beginning part while the case rates are going up.”

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