Mutation of SARS-CoV2 - current variants of concern - ECDC
#15,796
The last CDC update (Sunday night) listed 699 variants across 34 states, with 690 classified as B.1.1.7. Forty-eight hours later, the CDC is reporting a jump of 35%, bringing the confirmed count to 944 cases.
Given the low levels of testing across much of the country, these numbers are believed to only represent the tip of the iceberg.
Modelers at the CDC estimated last month that the B.1.1.7 variant could become dominant in the United States by March (see MMWR: Emergence Of SARS-CoV-2 B.1.1.7 Lineage — United States, Dec 29, 2020–Jan 12, 2021).
A more recent study, published 3 days ago on the preprint server MedRxiv, estimates that the number of B.1.1.7 cases in the United States doubles every 10 days, and also forecasts that it will become dominant by March.
Nicole L. Washington, Karthik Gangavarapu, Mark Zeller, Alexandre Bolze, Elizabeth T. Cirulli, Kelly M. Schiabor Barrett, Brendan B. Larsen, Catelyn Anderson, Simon White, Tyler Cassens, Sharoni Jacobs, Geraint Levan, Jason Nguyen, Jimmy M. Ramirez III, Charlotte Rivera-Garcia, Efren Sandoval, Xueqing Wang, David Wong, Emily Spencer, Refugio Robles-Sikisaka, Ezra Kurzban, Laura D. Hughes, Xianding Deng, Candace Wang, Venice Servellita, Holly Valentine, Peter De Hoff, Phoebe Seaver, Shashank Sathe, Kimberly Gietzen, Brad Sickler, Jay Antico, Kelly Hoon, Jingtao Liu, Aaron Harding, Omid Bakhtar, Tracy Basler, Brett Austin, Magnus Isaksson, Phillip G. Febbo, David Becker, Marc Laurent, Eric McDonald, Gene W. Yeo, Rob Knight, Louise C. Laurent, Eileen de Feo, Michael Worobey, Charles Chiu, Marc A. Suchard, James T. Lu, William Lee, Kristian G. Andersen
doi: https://doi.org/10.1101/2021.02.06.21251159
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Summary
As of January of 2021, the highly transmissible B.1.1.7 variant of SARS-CoV-2, which was first identified in the United Kingdom (U.K.), has gained a strong foothold across the world. Because of the sudden and rapid rise of B.1.1.7, we investigated the prevalence and growth dynamics of this variant in the United States (U.S.), tracking it back to its early emergence and onward local transmission.We found that the RT-qPCR testing anomaly of S gene target failure (SGTF), first observed in the U.K., was a reliable proxy for B.1.1.7 detection. We sequenced 212 B.1.1.7 SARS-CoV-2 genomes collected from testing facilities in the U.S. from December 2020 to January 2021. We found that while the fraction of B.1.1.7 among SGTF samples varied by state, detection of the variant increased at a logistic rate similar to those observed elsewhere, with a doubling rate of a little over a week and an increased transmission rate of 35-45%.By performing time-aware Bayesian phylodynamic analyses, we revealed several independent introductions of B.1.1.7 into the U.S. as early as late November 2020, with onward community transmission enabling the variant to spread to at least 30 states as of January 2021. 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.
This assumes, of course, that the California CAL.20C (aka ` L452R') variant - which made headlines 3 weeks ago (see PrePrint: Emergence of a novel SARS-CoV-2 strain (CAL.20C) in Southern California, USA) - doesn't give B.1.1.7 a run for its money.
Right now, CAL.20C isn't being tracked on the CDC's variant map, although there are reports of it turning up outside of California.
While the recent drop in COVID cases and hospitalizations in the United States - and around the globe - is a hopeful sign, the impact of these new, more transmisible variants is just beginning to be felt, and a spring resurgence is still a strong possibility.
Follow the link to explore the CDC's most recent updated Variant map.
