A highly mutated COVID-19 strain, has infectious disease experts worried. It’s not in Wisconsin

A new COVID-19 variant is being closely watched and has infectious disease experts concerned, weeks before a new COVID-19 vaccine is expected to become available.

The new variant, BA.2.86, has raised concerns among infectious disease experts because of the number of genetic mutations it has, which they worry could allow the virus to more easily evade immune responses built up through vaccines and prior infections.

BA.2.86 has more than 30 mutations compared with the strain dominant for much of this year, XBB.1.5, according to the Centers for Disease Control and Prevention. That is about the same number of genetic mutations as there was between the original omicron variant and prior variants.

“The concern is, could that cause a very similar spike epidemiologically, with more spread, more hospitalizations, more death?” said Ajay Sethi, professor of population health sciences at the University of Wisconsin-Madison. “It doesn’t have to replicate what we saw the last time (with omicron), … but it certainly is on everybody’s mind.”

Three cases of the variant, called BA.2.86, have been detected in the United States, including one in neighboring Michigan, according to by the global virus database GISAID.

Much is still unknown about the newly identified variant. Here is what public health officials and experts are saying now.

How serious is the BA.2.86 strain?

It is too soon to know how resistant to people’s immune responses the new strain will be, the CDC says.

Almost everyone in the United States has some protection against severe illness from COVID-19 because of vaccination, previous infection or both.

“The number of mutations is concerning,” Sethi said. “But at the same time, we have so much more immunity than we did since (omicron), and there’s reason to believe that the immunity that’s out there can actually work.”

In December 2021 and January 2022, when the original strain of omicron variant was first circulating in Wisconsin, a lot of people still had only vaccine-induced immunity to COVID-19. But now, many people have a broader level of immunity because they’ve been vaccinated and had a previous infection, said Aubree Gordon, associate professor of epidemiology and global public health at the University of Michigan.

“That’s going to give them more protection against any incoming variant than just having immunity against the original virus,” Gordon told the Detroit Free Press.

Has the BA.2.86 strain been detected in Wisconsin?

The BA.2.86 strain had not been detected in Wisconsin, as of Tuesday.

However, it is likely that variants are spreading undetected for longer periods of time than previous years, according to the CDC. That is because nationally, the level of genomic sequencing of COVID-19 has dropped from previous years. That’s the process by which labs determine what strain of COVID-19 caused an infection.

In July, labs in Wisconsin sequenced about 116 samples taken from positive COVID-19 tests, according to the Wisconsin State Laboratory of Hygiene. That’s compared to nearly 2,700 samples that were sequenced in July 2022, according to the state lab.

Now, states like Wisconsin rely more heavily on wastewater testing to track COVID-19. That is partly because most people with COVID-19 no longer get tested, or if they do, they test themselves at home, not at a public health testing site, Sethi said.

The Wisconsin State Laboratory of Hygiene sequences wastewater samples to identify which variants are circulating and where they are spreading. That data show that in August, several strains of the XBB lineage have been responsible for most COVID-19 infections in the state, according to the state lab.

Will BA.2.86 cause more severe illness?

It is too soon to know if the variant will cause more severe illness or if it will be more transmissible than other variants, according to the CDC.

Only 15 cases had been detected worldwide and reported to GISAID as of Tuesday. CBS News reported two of the three U.S. cases were mild, and that the severity of the third case was unknown. Three cases identified in Denmark had “normal” COVID-19 symptoms, according to the Danish public health and research institute.

People should not be especially concerned about BA.2.86 just yet, while much is still unknown, Sethi said.

Still, people should be vigilant about COVID-19, he said. That begins with a personal risk assessment, he said, in which you look at your and your family’s risk for severe illness from COVID-19, the level of spread in the community and the risk of exposure by going to an event or doing an activity — and then adjusting your behavior accordingly.

Sethi encouraged people to respect others’ decisions, such as a decision to wear a mask, because everyone has different comfort levels and levels of risk for severe illness.

What is causing the rise in COVID-19 hospitalizations?

The new strain’s detection has coincided with an uptick in COVID-19 hospitalizations in Wisconsin and across the country, though that increase began before BA.2.86 was identified and is likely being driven by other variants in circulation, Sethi said.

In Wisconsin, the number of weekly hospital admissions for COVID-19 has more than doubled since July, according to CDC data. In the week ending Aug. 19, about 140 people were newly admitted to a hospital with COVID-19, compared to 52 people in the week ending July 1.

Hospitalization rates for COVID-19 are still far lower than they were last summer, when between 400 and 700 COVID-19 patients were admitted to a Wisconsin hospital every week.

Increases of COVID-19 cases have occurred every summer since the pandemic began and have been driven by novel variants and by such things as summertime travel and heat waves that drive people inside, where they may more easily spread the virus, experts have said.

Will the new COVID-19 booster be effective against BA.2.86?

The CDC believes the new COVID-19 vaccine expected for September will be effective at reducing severe disease and hospitalization. But it’s too soon to know how much protection it will offer against BA.2.86.

At the very least, the vaccines will provide some protection against severe illness, Sethi said.

“It’s not an all-or-none thing,” he said. “There’s still some effectiveness.”

More:Where can I get a COVID vaccine and get tested in Milwaukee?

Will rapid tests and treatments work on the BA.2.86 variant?

Public health officials believe that rapid tests and PCR tests will still work in detecting the new variant.

Still, false negatives are always possible.

The Food and Drug Administration has previously recommended taking more than one test, using a different kind of test, if the first one is negative and if COVID-19 is suspected.

The CDC reported last week that treatments like the antiviral pills Paxlovid and molnupiravir, as well as the antivrial treatment remdesivir, should be effective against the variant, though monitoring is ongoing.