Volume of variants hits about 90% in latest MUSC testing cycle

May 14, 2021
Bar chart showing the variant B.1.1.7 becoming dominant.
This bar graph, created by Dr. Julie Hirschhorn, shows the dramatic rise of the U.K. variant B.1.1.7.

The volume of variants in coronavirus samples tested at the Medical University of South Carolina jumped from 40% for March to about 90% for April, newly released information shows.

“We are now in the world of variants of concern and variants of interest,” said Julie Hirschhorn, Ph.D., associate director of the molecular pathology laboratory and leader of MUSC’s COVID-19 variant analysis. Variants of concern and interest are categories created by the Centers for Disease Control and Prevention to track the coronavirus mutations cropping up around the world.

The variants have not caused a spike in cases locally. The most recent update from the MUSC Epidemiology Intelligence Project showed a 42% decrease in COVID-19 infections compared with the previous week for the Charleston Tri-county area.

But there is some concern that the variants pose a threat to people who haven’t been vaccinated yet. The dominant strain for April, the U.K. variant, is also called B.1.1.7. It’s represented in red in the chart at the top of this story. You can see it starts to show up in February and takes over in just two months.

“The B.1.1.7 variant strain is 50% more transmissible. You need to either be hypervigilant or get vaccinated. It's best to get vaccinated. That will help protect you from being hospitalized from COVID,” Hirschhorn said.

Dr. Julie Hirschhorn talks with Kristen Maurer, a medical technologist who is indexing each coronavirus-positive sample so 384 samples can be sequenced at the same time. 
Dr. Julie Hirschhorn, left, talks with medical technologist Kristen Maurer as they get ready to sequence coronavirus samples to check for variants. Photo by Sarah Pack

Experts say our vaccines appear to work against the current variants, greatly reducing the chance of infection, serious illness, hospitalization and death. Kids as young as 12 are now eligible to get the Pfizer vaccine.

But more than 200,000 South Carolinians were overdue for their second doses of COVID vaccines as of late last week. And the CDC estimates vaccine hesitancy at 16% for Charleston County, 18% for Berkeley and 19% for Dorchester.

Hirschhorn hopes that showing the rise of the variants will help convince some of those people to get vaccinated. “If more people have an idea of what variants are and what their potential is, and knowing what we're facing right now, maybe would move the needle on people getting vaccinated. The best we can do is provide the data. COVID is still here. It hasn't gone away.”

Her team plans to speed up its testing in the near future to give as close to real-time information as possible regarding variant numbers in the COVID-positive population being tested at MUSC. It’s also working to expand its testing to coronavirus samples taken from people around the state and look at the variants’ impact.

“One thing that's missing with the CDC surveillance is they often don’t have information like whether patients were hospitalized, what their symptoms were, what drugs they've taken and whether or not they worked. So our next step is to start looking at the data set as a whole, with patient information, to start being able to ask and answer questions about the different variants and impact that they may have.”

Part of her team's goal is to prepare for the future. “We're hoping that we can start creating a preparedness plan, so if a pandemic happens again, we’ll be ready to start testing and variant surveillance quickly to provide a rapid response to our community, state and the world.”