Although variant B.1.1.7 first identified in the UK is currently at a relatively low frequency in the United States, the paper says it doubles every week and a half, similar to what has been seen in other countries. The report estimates that this variant is 35-45% more transmissible than strains that appeared earlier in the United States and doubles about every 10 days in the country.
Last month, the modeling of the US Centers for Disease Control and Prevention predicted that variant B.1.1.7 could become the predominant strain in the United States by March. It is estimated that the virus is about 50% more transmissible.
“Our study shows that the US is on a similar trajectory to other countries where B.1.1.7 has quickly become the dominant variant of SARS-CoV-2, requiring immediate and decisive action to minimize COVID-19 morbidity and mortality. “, Wrote the researchers in the pre-printing of the study, which has not yet been evaluated or published.
In addition to the case groups in California, Florida and Georgia, many B.1.1.7 cases in the United States have not reported recent international travel, the report says, suggesting that “significant Community transmission of B.1.1.7 is already underway in the US “
Laboratories in the US are still sequencing only a small subset of coronavirus samples, the newspaper says, so it is unclear which variants are circulating in the country. Without “decisive and immediate public health action,” new, more transmissible variants are likely to have devastating consequences for COVID-19 mortality and morbidity in the United States in a few months, “the researchers warn.
Helix President Dr. James Lu told CNN last week that the company was looking for evidence that B.1.1.7 cases were on the rise and not just a product of increased genetic sequencing across the country.
“The growth rate here in Florida and Southern California is very similar to the type of growth we’ve seen before in the UK and Denmark … where B.1.1.7 has quickly become the predominant strain.” , said Lu.
It is unclear whether the pace of vaccination in the United States will prevent the strain from settling in places where it is not already circulating, he added.
“We are in a race between the vaccine and the new strains,” Lu said.
Dr. Anthony Fauci suggested last week that the US is not vaccinating people fast enough to stay ahead of the new options. This could reduce the vaccine’s efforts to reduce cases, he told CNN. “If variants and mutations come and start to become dominant, then that will eliminate some of the effects of the vaccine,” he said.
More than 610 cases of variant B.1.1.7 have been found in 33 states, according to the CDC. Most are in Florida and California. The first case in the US was announced on December 29, but the first known cases extend earlier. The analysis in the new study suggests that variant B.1.1.7 arrived in the United States as early as the end of November 2020.
The strain has also been found in at least 80 countries and territories around the world, the World Health Organization said last week.
The United States also recorded five cases in two states of variant B.1.351 first identified in South Africa and two cases in a state of variant P.1 first identified in Brazil.
Michael Nedelman and Andrea Diaz of CNN contributed to this report.