A new study finds that cases of a more contagious coronavirus variant are rapidly increasing in the United States, and significant community transmission may already be occurring.
Although the B.1.1.7 variant first identified in the UK is currently at a relatively low frequency in the United States, the paper says it’s doubling every week and a half, similar to what was observed in other countries. The report estimates this variant is 35% to 45% more transmissible than strains that appeared earlier in the United States.
Last month, CDC modeling predicted the B.1.1.7 variant could become the predominant strain in the United States by March. It estimates the virus is about 50% more transmissible.
“Our study shows that the U.S. is on a similar trajectory as other countries where B.1.1.7 rapidly became the dominant SARS-CoV-2 variant, requiring immediate and decisive action to minimize COVID-19 morbidity and mortality,” researchers wrote in the preprint, which has not yet been peer-reviewed or published.
The new study, posted Sunday on the preprint server MedRxiv, is a collaboration of researchers from several institutions and the company Helix, which is one of several labs that shares information on variants with the US Centers for Disease Control and Prevention.
In addition to groups of cases in California, Florida and Georgia, many B.1.1.7 cases in the United States did not report recent international travel, the report said, suggesting “significant community transmission of the B.1.1.7 variant is already ongoing across the U.S.”
US labs are still sequencing only a small subset of coronavirus samples, the papers said, so it’s not clear what variants are circulating in the United States. Without “decisive and immediate public health action,” new, more transmissible variants “will likely have devastating consequences to COVID-19 mortality and morbidity in the U.S. in a few months,” the researchers warn.
Some more context: More than 610 cases of this variant have been found in 33 states, according to the CDC. Most are in Florida and California. The first US case was announced Dec. 29, but the earliest known cases stretch back earlier. Analysis in the new study suggests the B.1.1.7 variant arrived in the United States as early as late November 2020.
The strain has also been found in at least 80 countries and territories around the globe, the World Health Organization said last week.