US health officials said the more contagious Delta variant now accounts for more than 80 per cent of new coronavirus cases in the country, a dramatic increase that has underscored how quickly the more contagious strain is spreading.
“[The] CDC has released estimates of variants across the country and predicted the Delta variant now represents 83 per cent of sequenced cases,” Rochelle Walensky, director of the Centers for Disease Control and Prevention, said during a hearing before the Senate health committee on Tuesday.
“This is a dramatic increase, up from 50 per cent for the week of July 3,” she said. In some parts of the country, the percentage was even higher, particularly in areas with low vaccination rates, she added.
The Delta variant, first discovered in India, has rapidly spread through a number of countries, including those with high vaccination rates, including the US and UK, alarming health officials and raising fears that restrictions will need to be reimposed to curb the spread.
Over the past weekend, Dr Vivek Murthy, the US surgeon general, warned that more US cities might follow the lead of Los Angeles and reintroduce mask mandates for indoor settings, even among people who are fully vaccinated, to curb the spread of the Delta variant.
Over the past week, the US had averaged 239 deaths a day from Covid-19, an increase of almost 48 per cent over the previous week, Walensky said.
She previously warned that US was experiencing a “pandemic of the unvaccinated” with cases rising quickly again, particularly among those who are unable or unwilling to get vaccinated despite plentiful supply.
More than 161m Americans are fully vaccinated, representing about 48.6 per cent of the US population, according to CDC data. In almost two-thirds of counties in the US, less than 40 per cent of people had been vaccinated, Walensky said on Tuesday.
The Biden administration has expressed concern that vaccine hesitancy is being fuelled by misinformation shared on social media platforms and has engaged in a public spat with Facebook.
“The message from the CDC remains clear: the best way to prevent the spread of Covid-19 variants is to prevent the spread of disease, and vaccination is the most powerful tool we have,” Walensky said.
Kate Bedingfield, the White House director of communications, told CNBC on Tuesday that she thought social media companies should be held accountable for vaccine misinformation published on their platforms. She said the White House was “reviewing” Section 230 of the Communications Decency Act, which grants social media companies legal immunity for content which users publish on their platforms.
There have also been cases reported among fully vaccinated individuals. On Tuesday, a senior spokesperson in the office of Nancy Pelosi, the speaker of the US House of Representatives, was confirmed to have tested positive for Covid-19 after meeting Democratic members of the Texas state legislature last week who later tested positive for the virus.
Additional reporting by Kiran Stacey and James Politi in Washington