Anthony Fauci said the Delta variant of Covid-19 now accounts for about one in five new infections in the United States, describing the new strain as the “greatest threat” to the country’s efforts to quash the pandemic.
Fauci, chief medical adviser to President Joe Biden, told a press conference on Tuesday that the new strain, which was first discovered in India, had a “doubling time of about two weeks” at United States and “followed the pattern” of the Alpha strain, which was first identified in the United Kingdom, became the dominant strain in the United States in the spring.
Fauci revealed that 20.6% of Covid-19 samples genomically sequenced in the United States in the two weeks ended June 19 were the Delta variant, up from 9.9% a fortnight earlier and only 2.7 % of samples in the two weeks ended May 22. .
“The transmissibility is unquestionably superior to that of the wild type and the Alpha variant,” he said, comparing Delta to the original strain of Covid-19 that originated in Wuhan and the variant first discovered in the year last in UK, respectively.
Fauci referred to a study from Imperial College London which found young people were “behind the British wave” of new Covid-19 infections there, and also said that the Delta variant was the dominant strain among the sequenced samples.
“Similar to the situation in the UK, the Delta variant is currently the biggest threat in the US to our attempt to eliminate Covid-19,” he said.
The good news, he said, is that the vaccines are effective against the new variant, with the BioNTech / Pfizer and Oxford / AstraZeneca vaccines each being 90% more effective at preventing hospitalizations for the Delta variant after two doses.
The most recent figures on the spread of the Delta variant in the United States followed a White House concession earlier today that the country would miss Biden’s target of having 70% of adults Americans receive at least one dose of a vaccine by July. 4. The current level is 65.4 percent.