In a massive surge in cases of Delta variant of COVID-19, US health expert Dr Anthony Fauci said that from 10% two weeks ago, it now makes up 20% of the new cases recorded in the country. He called the variant, which was first identified in India, as  the “greatest threat” to the USA’s attempt to eradicate the COVID-19 pandemic, reported news agency PTI.

Also read: What is Delta plus variant of COVID-19? Should we worry?

Speaking at a White House briefing on COVID-19 on Tuesday, Fauci said, “We have seen, as was the case with B.1.1.7 (Alpha variant, first identified in the UK), we seem to be following the pattern with the Delta variant with a doubling time of about two weeks if you look from May 8 with 1.2 to 2.7% to 9.9% and as of a couple of days ago 20.6% of the isolates are Delta.”

“Similar to the situation in the UK, the Delta variant is currently the greatest threat in the US to our attempt to eliminate COVID-19,” White House Chief Medical Advisor warned.

In the UK, Delta has become the dominant strain,  surpassing the Alpha variant first discovered in the country. Delta now makes up more than 90% of new cases and delayed the UK’s scheduled reopening.

Fauci said that the transmissibility of the Delta variant is unquestionably greater than the wild type SARS-CoV2 as well as the Alpha variant, adding that it is associated with increased disease severity as reflected by hospitalisation risk compared to the Alpha variant.

Also read: COVID’s Delta variant becoming globally dominant: WHO

In what he called a “good news”, the health expert said that the US vaccines are effective against the Delta variant.

“The effectiveness of the vaccines, in this case, two weeks after the second dose of Pfizer BioNTech with 88% effective against the Delta and 93% effective against the Alpha when you are dealing with symptomatic disease,” Fauci said.

“Conclusion, we have the tools, so let’s use them and crush the outbreak,” he asserted.

Also read: 4 lions infected with delta variant of COVID-19 at Tamil Nadu zoo

The US Centers for Disease Control and Prevention (CDC) has classified the Delta as a ‘variant of concern’. The other ‘variants of concern’ in the country are the Alpha (B.1.1.7), Beta (B.1.351), Gamma (P.1) and Epsilon (B.1.427/B.1.429).

Last month, the World Health Organisation (WHO) classified the Delta variant as a variant of concern.