Latest COVID variant report shows strain found in U.K. increasing

Photo of Peter Yankowski

The more infectious and possibly deadlier variant of COVID-19 first detected in the United Kingdom, known as B.1.1.7 made up a majority of cases sequenced in the past week in Connecticut, the latest numbers released Thursday show.

B.1.1.7 made up more than 60 percent of cases genomically sequenced by researchers at Jackson Laboratory and the Yale School of Public Health.

The variant is thought to spread between people more easily by about 50 percent, according to the Centers for Disease Control and Prevention. And a study published in February found the strain also likely results in a higher risk of hospitalization and death.

As of Thursday, 1,033 cases of B.1.1.7 have been confirmed in Connecticut, up 9.6 percent from the week before.

If anything, the numbers put that variant behind schedule — the CDC had predicted the variant would become the predominant strain in the U.S. in March.

In the U.K., the variant caused the country to go into a second lockdown over the winter as the variant rapidly expanded to become the dominant strain.

“While we expect B.1.1.7 to continue this trend until it dominates (like in the UK), the good news is that we are seeing a reduction in both B.1.1.7 and non-B.1.1.7 cases,” Nathan Grubaugh, Assistant Professor of Epidemiology at the Yale School of Public Health, wrote in a tweet Thursday.

Those numbers put the B.1.1.7 variant firmly ahead of two strains first detected in New York state, known as B.1.526 and B.1.526.1, which together made up a little under 19 percent of cases sequenced in the past week.

While the strain that originated in the U.K. is classified as a “variant of concern” by the CDC, the two strains first detected in New York are considered variants “of interest,” meaning they have limited expansion, but may be linked to outbreaks or have genetic markers that could allow them to escape treatments or transmit more easily.

Overall, variants of concern and interest made up a little more than 83 percent of all cases researchers sequenced this week— down by more than 6 percent from the week before.

In the case of the two variants first found in New York, researchers believe both have mutations that could allow them to escape some antibody treatments given to patients who become sick with the disease. It’s thought that both could also partially escape the protection granted by the vaccine or in people who have had COVID-19 and recovered.

Researchers also found two more cases of B.1.1.7 with a mutation that’s believed to help the virus evade antibodies. The mutation, known as E484K, also shows up in the P.1 strain first found in Brazil, as well as the B.1351 strain first detected in South Africa.

Grubaugh said the two mutated samples of B.1.1.7 were unrelated, and likely showed up or were brought into Connecticut on their own.

In total, three cases of B.1.1.7 have been detected with the mutation, according to the report.

“So far this is not too alarming given their low frequencies, but something that we keep an eye on,” Grubaugh wrote.