KANNAPOLIS — Duke University researchers based at the N.C. Research Campus for months have been observing 1,426 people as part of a study on COVID-19 prevalence and immunity.

Those 1,426 people were already participants in the MURDOCK Study, a longitudinal health study being conducted by Duke. The COVID-19 component of the study is based on Cabarrus County. Of those 1,300 people, 300 are part of a testing cohort.

Principal Investigator Dr. Kristin Newby said the participants are doing a great job getting information back to the researchers and taking safety precautions. A dozen of those people have tested positive since they began testing in August, which Newby said is smaller than the prevalence in the general population being reported by news outlets, though that number may change.

“We haven’t had a chance yet to finish all of our statistical analyses and project that over the Cabarrus County population,” Newby said.

Newby said there is a bias in populations who participate in health studies toward being more aware of their health than people who do not, though the study tried to reach out to reflect the demographics of the county as best it could.

Mark Seifel, a testing cohort participant and engineer, said he has always tried to stay healthy and during the pandemic has taken the recommended precautions, but he still contracted COVID-19.

Seifel recovered with mild symptoms like backache and headache.

“Pretty much by the time I got the results I knew I had it,” Seifel said.

His second test came back positive as well, even after he felt better.

Seifel said he was not worried when he tested positive and started exhibiting symptoms because he is healthy and none of the symptoms were severe enough to make him concerned.

Seifel has been sending off nasal swab specimens regularly and has his blood drawn every two months to check for antibodies.

Newby said she estimates that about 5.5% of Cabarrus County residents may have antibodies, based on projections from the testing cohort. So a lot of people are still at risk.

“Our main message is keep doing what you’re doing,” Newby said. “Now is not the time to give up with the vaccine seemingly around the corner, within the next few weeks at least rolling out initial coverage and for the greater population probably over the next six months or so. But there are still a lot of vulnerable, at-risk people out there.”

Newby said researchers will monitor the changes in the pandemic and update surveys to give participants timely questions related to what is going on. That includes questions like a recent addition asking participants if they would take a vaccine.

“So we get an idea kind of what the skepticism or willingness is in the population about a vaccine,” Newby said.

The collection process itself has to keep up, too. Right now, the study is still at the point where it can bring people in to draw blood for antibody testing, but Newby said that testing may have to pause if the pandemic continues to worsen in North Carolina. The study is looking into at-home blood collection equipment.

“We have to have other means for completing the study,” Newby said.

Newby said the study will continue through a point when the vaccine is widespread and will be able to follow the curve after vaccination, seeing if there is a decline in infection rates and a climb in immunity as part of a larger network of studies observing the issue.

The other issue that requires research is the durability of the immunity provided by the vaccine. Vaccine trials have proven effective so far and the virus has not been prone to mutation, but there could be other coronavirus health threats in the future.

“I think there is still some uncertainty there, and we won’t know for a while how long immunity lasts,” Newby said.

Editor’s note: This article was updated Dec. 9 at 4:41 p.m. to correct the number of people participating in the study and to clarify the percentage of people who may have antibodies from coronavirus infections. We apologize for the errors.