The highly contagious U.K. variant of the coronavirus known as B.1.1.7 is now the predominant strain circulating throughout the Chattanooga region, according to Baylor School research scientists.
Several other variants of concern — California variants B.1.427 and B.1.429 and New York variant B.1.526 — were also recently detected in positive COVID-19 samples analyzed by scientists at Baylor's Esoteric and Molecular Laboratory.
Baylor scientist Elizabeth Forrester said that B.1.1.7 began showing up in a majority of the lab's positive samples about a week ago. The lab only tests a fraction of the area's COVID-19 samples, but Forrester said the sample size is large enough that she's confident that B.1.1.7 is now the most prevalent variant in the region.
In January, Tennessee Health Commissioner Dr. Lisa Piercey said that she expected B.1.1.7 to be the predominant strain in the state by March.
B.1.1.7 is at least 50% more transmissible than previously common coronavirus strains, and an increasing number of studies indicate that it is also more deadly.
The California variants were recently classified as "variants of concern" by the U.S. Centers for Disease Control and Prevention. They're believed to be around 20% more transmissible than earlier strains, meaning they are not as contagious as the U.K. variant.
However, California's variants appear to be better at evading COVID-19 medications and vaccines. One of the California variant cases detected by the Baylor lab was a "vaccine breakthrough," the term for when an individual becomes infected despite being fully vaccinated against COVID-19.
"We weren't able to vaccinate fast enough before some of these more transmissible variants began circulating, and now they're the dominant strains that we're seeing," Forrester said.
COVID-19 hospitalizations in Hamilton County have begun trending up after reaching their lowest point since June on March 13, which was 34 inpatients, according to data from the Hamilton County Health Department. As of Wednesday, there were 63 inpatients — a trend that could be attributable to B.1.1.7, which was blamed for a dramatic rise in hospitalizations in the U.K.
While new cases in Hamilton County appear relatively stable, the number of COVID-19 tests being conducted continues to decline, and the county's test positivity rate has grown to around 12%. Those numbers indicate that not enough testing is being done to effectively track where the virus is spreading, and Forrester worries that options for free testing and public interest are waning as the new variants are gaining steam.
She said the lab is getting an increasing number of positive samples from people who have only received one vaccine dose, which is another reason why the public should continue practicing precautions.
"[The vaccines] are really effective, but they're not 100%," she said. "With the amount of virus that's still circulating out there, it's going to cause problems if people aren't masking and socially distancing and doing all those things — it just gives the virus another opportunity to find a mutation that's going to make these vaccines even less effective, which is going to be problematic for everybody."
Robert Bednarczyk, an assistant professor of global health at the Emory University Rollins School of Public Health, echoed those concerns.
"Any person who's infected can potentially house the next newly emerging variant. That's why any steps we can take to control the spread and control the transmission of this virus, whether it be vaccines or other non-vaccine ways, is going to be important," Bednarczyk said. "The more we can restrict getting sick the more we can reduce the risk of potentially a much more serious mutated variant emerging and really negatively impacting many of the hard-fought gains."
As a result of Baylor's recent findings, Forrester said the lab is now sequencing — the genetic testing used to identify variants — all positive COVID-19 samples.
Forrester is also confident that the variants are more prevalent than what's reported by the U.S. Centers for Disease Control and Prevention because few laboratories are capable of conducting sequencing. The process is more costly and time consuming than routine testing.
"We will continue to do this as long as we have money, but we're kind of doing this on our own at this point, which we're happy to do, because I think it's really important," she said.
As of Wednesday, the CDC shows Tennessee only having 168 reported cases of B.1.1.7 and one confirmed case of the South African variant known as B.1.351. That means only 16 new variant cases in Tennessee have been reported and uploaded to the CDC website since Feb. 12.
"We're just showing a little sliver of the pie," Forrester said. "But I think whatever sliver we put out there, you can assume it's a lot more prevalent than what's being reported, because we're the only ones [in the region] sequencing."
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