The coronavirus variant first detected in the U.K. late last year now accounts for up to 10% of COVID-19 cases in the U.S., officials said Friday. The 10% marks an uptick in prevalence, Dr. Rochelle Walensky, the director of the Centers for Disease Control and Prevention (CDC) said. Just a few weeks ago, the variant accounted for about 1-4% of illnesses, she added.
Officials had previously predicted the B.1.1.7 variant, estimated to be about 50% more transmissible than the wild strain first detected in the U.S., would become the dominant strain in the country by mid-March. Walensky said that the U.S. "may now be seeing the beginning effects" of the variants in the most recent data, which reflected an uptick in several seven-day averages.
The recent trend of declining rates of hospitalization admissions, new cases and deaths has started to level off, she said, signaling a "concerning shift in trajectory." Walensky added that the declines had followed the highest peak the country had seen during the pandemic.
The CDC is also monitoring the discovery of two new variants, one in New York and the other in California, which "also appear to spread more easily and were contributing to a large fraction of infection in those areas," Walensky said.
"We may be done with the virus, but clearly the virus is not done with us," she said.
Dr. Anthony Fauci, the nation’s leading infectious disease expert, added that vaccine developers are taking several approaches to combat the worrisome variants. One approach, he said, is to create new boosters specifically targeting the variant, such as the one Moderna developed against the South Africa variant. Another option, he said, is simply adding a boost to the existing vaccine to higher the titer of antibody against the wild type of virus.
While at least one booster is nearing trial, Fauci called on Americans to get vaccinated as soon as possible to lower the rates of virus in the community.
"Viruses will not mutate if you don’t give them the opportunity to spread and replicate," he added, echoing Walensky’s call to double down on public health measures.
Andy Slavitt, the White House senior advisor for COVID-19 response, also urged against relaxing restrictions and mitigation measures despite the recent increase in vaccination efforts.
"The progress we have made [is] better than where we were weeks ago but it is nowhere near the baseline we need to achieve as a country," Slavitt said.