B117 Variant of COVID-19 Becoming More Common Among Sampled Cases, Minnesota Health Leaders Say

(KNSI) – The proportion of COVID-19 cases in Minnesota caused by the more contagious B117 variant appears to be growing, say state health officials.

The B117 variant of COVID-19, which was first identified in the United Kingdom, is considered a variant of concern because researchers say it spreads more easily than other strains of the virus. Last week, Minnesota Department of Health leaders linked the B117 variant to a recent increase in new cases.

To determine which strain of COVID-19 caused an infection, a lab must process the sample through whole genome sequencing. State epidemiologist Dr. Ruth Lynfield says the country does not have the capacity to test every positive sample. However, the state has identified 479 cases of the B117 variant as of Tuesday, and Lynfield says the occurrence of B117 in those lab-sequenced samples is growing.

“When we look at one of our partner labs [that] has been sending specimens for sequencing, we estimate that 50 to 65 percent of COVID positive specimens tested March 16th through March 20th were B117,” Lynfield said. “This is an increase compared with specimens tested March 10th through the 15th, in which 38 to 44 percent of those specimens were estimated to be B117.”

While some COVID-19-positive samples are chosen at random to be sequenced, Lynfield says the known B117 cases are skewed toward certain groups. She says the state prioritizes whole genome sequencing for people who test positive less than 14 days after traveling, those who have a case connected to a regional outbreak and those who catch COVID after getting vaccinated — rare occurrences that are called breakthrough cases.

Lynfield said people who have known cases of the B117 variant have a median age that is slightly lower than the state’s median age.

“When we look at the identified cases, the hospitalization rate, so far, is similar, but the age of the person being hospitalized — the median age is a little bit lower,” Lynfield said.

The state is working to increase the amount of COVID samples it sequences, and Lynfield said as MDH gets more data, it could become more clear if B117 will become the dominant strain of COVID-19 in circulation in Minnesota and, if there is another spike in cases, if the hospitalization and death rate will change compared to earlier case surges.

“What we don’t yet know but what we hope to see and expect to see, frankly, is that the composition of those cases and those hospitalizations is changing, skewing towards younger people with milder illness,” Health Commissioner Jan Malcolm said. “So as some of the most vulnerable are vaccinated, we hope to see — I think we are seeing early signs — but hope to see … that the proportion of cases that are in the ICU or that result in death is lower than in prior surges.”

Nearly 80 percent of Minnesotans age 65 and older have received at least one dose of a COVID-19 vaccine. Malcolm says over half of those seniors are now fully vaccinated. Overall, roughly 1 in 4 Minnesotans are at least partially vaccinated against COVID-19.

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