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Greenville Business Magazine

Research Probes for Coronavirus Guidance

By Liv Osby

Thousands of South Carolinians are helping state health officials better understand the coronavirus by volunteering for research that is looking at infection rates and immunity over time.

Slated to run through October, the work is already yielding interesting results.

For instance, among unvaccinated people who tested positive for the virus, at least a third lost antibodies over time, making it possible for them to be reinfected, said Dr. Melissa Nolan, assistant professor and epidemiologist with the University of South Carolina Arnold School of Public Health.

“It’s a gradual decline, but we start to see that around three months. So it’s important for them to get vaccinated,” she said. 

Dr. Melissa Nolan

Nolan said that vaccination is lower than she would like at UofSC and that they see reinfections at the school.

“College students are living in dorms, they are together at various events and are congregating more than adults,” said Dr. Virginie Daguise, director of the Bureau of Chronic Disease and Injury Prevention at the state Department of Health and Environmental Control. “They are more socially active.”

 Dr. Virginia Daguise

Also, those who tested positive are three times as likely to have had a friend or family member who had Covid as someone who didn’t, the study shows.

“People are getting it from close social interactions,” Nolan said. 

But perhaps surprisingly, only about 13 percent of participants had a natural immunity, signaling that they had been infected with the coronavirus previously. That is likely a reflection of previously infected people losing antibodies over time, she said.

Called the STRONG study – for Sampling and Testing Representative Outreach for Novel coronavirus Guidance – the project is looking at randomly selected volunteers age 5 and older from around the state. It’s being led by Nolan and Daguise.

Volunteers complete a confidential survey about their vaccine status, mask use, age and job status, among other things, and are tested to determine current and past coronavirus infection. 

The study will be statistically representative of the state, the researchers said, with more people coming from areas with higher population density.

“Early on in the pandemic, DHEC wanted more representative information than just those coming in for testing,” said Nolan of the reason for launching the study. 

“This will give us a better idea of where we’re seeing clustering … and looking at immunity,” she added. “We are looking at a lot of variables.”

The researchers are looking at different groups, or cohorts, of residents over time and have found that what they see in the first group is not necessarily the same thing they see in those that come after it.

“It’s going to be very interesting to follow these cohorts and compare them to each other to see how the face of Covid is changing in our state,” said Daguise. “It’s one more piece of the puzzle.”

For example, she said, when the research began in October of 2020, vaccines weren’t yet available.

“So this is very much developing,” she said. “We are following individuals as interventions are coming into play.”

The research shows that the incidence of infection was higher among children in the second cohort than the first, Nolan said. 

A fourth group will run from Aug. 2 to Sept. 10 as school starts, so it will be interesting to see what that uncovers, said Daguise.

The research team will analyze hotspots of infection and levels of immunity as well as produce models that forecast the disease trajectory.

In the third cohort, which took place during May and June, hotspots were noticed in Greenville, Edgefield, Florence and Spartanburg counties, the research shows.

“We’re trying to better understand the patterns of transmission within specific populations,” said Nolan, “and we’re looking for existing immunity within individuals who have already recovered from infection.”

The study also is expected to provide information about how the state might better allocate its resources, such as testing and vaccination sites, Daguise said.

Among other revelations from the research – 

  • Nursing home workers or those providing front-line medical staff in the second cohort, which was done in February, had greater odds of testing positive for the virus or antibodies than others – seven times and 4.6 times, respectively.

  • Those 70 or older were 2.2 times more likely to test positive. 

  • And 61 percent of volunteers with a positive PCR test had no symptoms at all.

Nearly half of those in the second cohort – 46.6 percent – had a high-risk underlying health condition, the research shows. 

And about 19 percent in that cohort had gotten at least one dose of the vaccine, but the researchers explained that the vaccine wasn’t widely available to all age groups by February. (Just over 80 percent of the May-June group had had at least one dose of vaccine.)

Some 71 percent of participants said the vaccine is safe and almost 69 percent said it’s effective, the research shows. 

And only 13 percent were hesitant about getting vaccinated.

About 10 percent of those in the third group were parents with children at home, according to the research. And about a fifth of them reported their child “had had a Covid-19 exposure at a daycare or school, with most of these children having less than five high-risk exposures requiring quarantine.” 

Partners in the study include Clemson University, Health Sciences South Carolina, the Medical University of South Carolina, Prisma Health, the South Carolina National Guard, the South Carolina Office of Rural Health and the South Carolina Primary Health Care Association.

“This is an exciting, once-in-a-lifetime opportunity for South Carolinians to directly support public health experts’ understanding of this new and deadly disease that continues to impact our state and nation,” said Daguise.

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