Cases of this COVID variant tripled in just two weeks, CDC estimates

Incidence of a COVID-19 variant appears to have increased threefold in the U.S. in recent weeks, federal tracking showed.

The BA.2.86 variant – a mutated COVID-19 strain previously thought to be uncommon – is projected to account for nearly one-tenth of circulating viruses, according to the Center for Disease Control and Prevention’s Nowcast variant tracker posted Monday. Two weeks ago, the variant made up 3% of cases. These figures are based on estimates of circulating variants.

“The numbers are less important,” Dr. Perry Halkitis, the dean of the Rutgers School of Public Health, in New Jersey, told USA TODAY. “The pattern is more important. And it looks like it's growing.”

The most recent estimate that BA.2.86 makes up 9% of COVID cases is not a firm number. Health officials say the variant likely accounts for 5% to 15% of circulating variants in the U.S.

Testing is considered a less reliable indicator of disease prevalence. But the increase in hospitalizations and deaths from COVID-19 should cause concern, Halkitis said. Colder temperatures in densely populated regions such as the New York area may account for increases in the Northeast in recent days, he added.

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COVID-19, like other viruses, is constantly changing through mutations that make it easier to spread or are resistant to medicines or vaccines.

BA.2.86 comes from the BA.2 lineage, and it’s a sub-variant of omicron, which came to dominate cases two years ago. BA.2.86 also has an offshoot, JN.1, but it appears rare for now.

Updated COVID-19 vaccines are expected to increase protection against BA.2.86, the CDC said.

BA.2.86 doesn’t appear to be driving increases in infections or hospitalizations, the CDC said. Both the CDC and the World Health Organization believe the variant’s risk to public health is low for severe illness compared to other variants. But on Aug. 21, WHO reclassified BA.2.86 as a "variant of interest" amid global increases in recent weeks.

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CDC data showed the Northeastern region including New Jersey and New York saw 13% of cases derived from BA.2.86, the highest figures recorded of the variant.

In a statement, the New York State Department of Health said the BA.2.86 variant has been detected in state wastewater, a tool for COVID surveillance, since late August and has been increasing in proportion during recent months.

New York health officials said BA.2.86 cases are increasing across the state. However, officials said they anticipated this uptick due to BA.2.86 reportedly being more transmissible compared to other circulating variants.

The New Jersey Department of Health has noted increasing numbers of BA.2.86 specimens since mid-October, department spokesperson Dalya Ewais wrote in an email. New Jersey is expected to see similar trends as the CDC's Nowcast estimates for the region, she added. Still, she said, BA.2.86 isn't likely to reach levels of the first COVID-19 outbreak in spring 2020, or the omicron variant.

Health officials from New Jersey and New York encouraged people to stay up-to-date on COVID-19 vaccines. If symptoms develop, people should get tested and stay home.

Eduardo Cuevas covers health and breaking news for USA TODAY. He can be reached at EMCuevas1@usatoday.com.

This article originally appeared on USA TODAY: COVID-19 variant BA.2.86 cases triple in two weeks, CDC estimates