155 breakthrough COVID-19 cases reported in SC: What are they?

COLUMBIA, S.C. (WCSC) - A fraction of one percent of people who are fully immunized after getting COVID-19 vaccine still end up contracting the virus.

To date, there have been 155 of these “breakthrough” cases reported in South Carolina, according to the Department of Health and Environmental control.

“I think that’s evidence the vaccine is working,” Assistant State Epidemiologist Dr. Jane Kelly said. “These breakthrough cases are by in large asymptomatic or mild disease.”

DHEC defines a “breakthrough” case as one where the patient has tested positive for the coronavirus 14 days or more after receiving a full COVID-19 series, one shot of the Johnson and Johnson vaccine or two shots of the Pfizer or Moderna vaccine.

Dr. Kelly says DHEC investigates these cases but couldn’t offer more details on the health status of the 155 patients reported as of publication.

“We do have an idea of their clinical course, but of course with some of these the investigation are on going…What I can say is there is no trend that it is occurring in a certain age group, or which vaccine they received,” Kelly said.

University of South Carolina infectious disease expert, Melissa Nolan said these cases can emerge for a variety of reasons.

“It has to do with their own personal genetics and immune status. It has to do with the type of exposure they get… more routine, high-risk exposure. And of course, whether you are getting exposed to variants,” she said.

While the variants aren’t any more deadly, according to Kelly, they can be more infectious.

The variant from South African which has been detected in South Carolina and around the world is able to circumvent the protection of a vaccine, according to data from a study out of Israel.

National infectious disease expert Dr. Anthony Fauci called the study “misleading” because vaccinated people are still well-protected against severe disease and other experts have pointed out the study’s sample size was small and it has not been peer-reviewed.

Nolan says there are three types of antibodies to consider that are working to protect us from getting infected.

First, IgA antibodies are made after you contract COVID-19 and recover. Nolan says these are the frontline defense.

“Think of that as your body’s ability to stop the virus from getting in your body,” she said.

The second protection is IgG and IgM antibodies. These are like soldiers in our bodies which can be made by the vaccines. They can fight the virus from making us really sick or making us sick at all.

“That’s why we say it can stop severe disease but not necessarily the disease itself,” Nolan says.

But what about the variants like the one from South Africa?

DHEC Assistant Epidemiologist Dr. Jane Kelley says that’s where the third defense comes in.

“Because it has that little more resistance to antibodies, it’s better able to get in the cell, and that’s why if you’ve been exposed you might get mild disease with the South African variants because it’s a little better at fighting antibodies. But T cells will still get it,” she says.

T-cells last longer than antibodies and can help fight the virus if our other defenses aren’t working and prevent severe disease.

Kelly said of the 155 breakthrough cases, DHEC is still doing research to determine whether any of the patients became severely ill or died. She said the majority of such cases, however, are mild or asymptomatic.

And Kelly and Nolan both stress the spreading of the variance, the fact that South Carolina has not yet reached herd immunity, and these “breakthrough” cases should just serve as a reminder to people of the importance of wearing masks, socially distancing, and hand washing.

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