'Razor Blade Throat' COVID Subvariant Sickens More In CA

CALIFORNIA — A new COVID-19 subvariant born from Omicron has become the dominant strain in the U.S. and cases have been spreading throughout the Golden State in recent weeks.

Dubbed "Nimbus" (NB.181), the highly contagious version of coronavirus is characterized by its extremely painful sore throat, described as "razor blade throat" overseas.

Those who have contracted the strain and previously similar variants have described intense throat pain akin to having a throat lined with shards of glass.

“Before Omicron, I think most people presented with the usual loss of taste and smell as the predominant symptom and shortness of breath,” Dr. Peter Chin-Hong, a UC San Francisco infectious disease expert told the Los Angeles Times.

These days, those sickened by COVID are less likely to be hospitalized, but patients tend to focus on other symptoms, such as a painful sore throat, Chin-Hong said.

Nimbus, which originated in China, accounts for an estimated 37 percent of cases nationwide, according to data collected over two weeks starting on June 7.

“What sets NB.1.8.1 apart is how quickly it spreads,” said Dr. Magdalena Sobieszczyk, chief of the Division of Infectious Diseases at NewYork-Presbyterian/Columbia University Irving Medical Center.

“It has a genetic advantage: mutations that make it easy for it to bind to receptors on human cells. The mutations could allow NB.1.8.1 to spread faster and therefore infect more people.”

An uptick in cases is arriving just as the summer travel season is about to begin, which could spell trouble for the Golden State with throngs flocking to vacation here.

“We will probably see a spike in COVID cases this summer because people may be traveling more,” Sobieszczyk said. “But any huge spike will be offset by people engaging in outdoor activities, in areas with more ventilation.”

Luckily, experts say that the traditional methods of warding off COVID-19 are effective against Nimbus, such as vaccination, wearing a mask and washing hands.

Nimbus first reached the U.S. likely in March, around when it was first detected through airport screening programs for international travelers, TODAY reported. In May, the strain reached the Golden State.

California's Department of Public Health told the Los Angeles Times that the subvariant accounted for 55 percent of circulating virus in the state. That figure is up by two percentage points since April, the agency said.

Dr. Elizabeth Hudsen, regional chief of infectious diseases for Kaiser Permanente Southern California, told the Times that experts are seeing elevated levels of COVID-19 in wastewater and an uptick in the test positivity rate.

Levels detected in wastewater across the Southland varied, she said.

"Ventura and Los Angeles counties are seeing low-to-moderate levels, Riverside is reporting low levels, while San Bernardino is experiencing high activity,” Hudson said.

Statewide, COVID levels found in wastewater are at a "medium" level, according to June 12 data from the state's health department.

The subvariant is spreading as federal authorities dramatically scaled back the Centers for Disease Control and Prevention's vaccine recommendations. Now, the CDC does not offer guidance on whether pregnant women should get a COVID vaccine. The guidance also asks parents to consult a doctor before getting their children vaccinated.

The U.S. Health Secretary, Robert F. Kennedy Jr., who is a known vaccine skeptic, also shook up the Advisory Committee on Immunization Practices on June 11, drawing criticism from many in the public health and medical communities.

Kennedy announced eight new members to serve on the committee after removing all 17 of the previous members.

Health experts have also noted that multiple new committee members appointed on June 11 have voiced anti-vaccine views that are not evidence-based.

Abram Wagner of the University of Michigan’s school of public health, who investigates vaccination programs, said he’s not satisfied with the composition of the committee.

“The previous ACIP was made up of technical experts who have spent their lives studying vaccines,” he said. Most people on the current list “don’t have the technical capacity that we would expect out of people who would have to make really complicated decisions involving interpreting complicated scientific data.”

The Associated Press contributed to this report.