The Delta variant of SARS-CoV-2 now accounts for 83 percent of all sequenced COVID-19 cases in the US, CNBC reports.
It adds that Rochelle Walensky, the director of the Centers for Disease Control and Prevention, told Congress Tuesday that this is a dramatic rise from earlier this month when the Delta variant accounted for about half of sequenced COVID-19 cases in the US. She added that in some parts of the US, especially where vaccination rates are low, that percentage is even higher, Business Insider reports.
Walensky also noted that there has been an increase in COVID-19 fatalities, rising to an average 239 deaths per day, according to CNBC. Most deaths, she said, are among unvaccinated individuals, Stat News adds.
The Delta variant is thought to be even more transmissible than the Alpha variant that was itself found to be more transmissible that the original virus, CNBC adds. "The reason it's so formidable is the fact that it has the capability of transmitting efficiently from human to human in an extraordinary manner, well beyond any of the other variants that we've experienced, up to now," Anthony Fauci, the White House chief medical advisor, also said during the hearing, according to CNBC.