Delta variant accounts for more than 80% of U.S. cases

The Delta variant of the coronavirus is the cause of more than 80% of new U.S. COVID-19 cases, but the authorized vaccines remain more than 90% effective in preventing hospitalizations and deaths, said top U.S. infectious disease expert Anthony Fauci during U.S. Senate hearing on Tuesday.

This report produced by Freddie Joyner.

The fast spreading Delta variant now accounts for more than 80% of new U.S. COVID-19 cases - this is according to top U.S. infectious disease expert Dr. Anthony Fauci who spoke on Capitol Hill​ Tuesday during a Senate hearing… COVID cases are sharply higher across the country and deaths are rising too - up nearly 48% from the previous week... But Fauci said - so far - vaccines are holding up against the threat.

“The fact is that, however, and the importance of vaccination is that our vaccines that we're using in this country are very effective against this variant, particularly I point out, to the situation regarding advanced disease leading to hospitalizations and deaths where it's still well in the 90 percent of effectiveness.” But millions of Americans are still not vaccinated.

Causing alarm among U.S. health officials who are urging Americans to get their shots - a message shared Tuesday by Republican Senator Richard Burr of North Carolina.

“Covid won't just go away.

We need all Americans who can get the vaccine to get the vaccine.

If you won't do it for yourself, do it for your friends, your families, for your neighbors and your local community.

(flash) Not only is a Delta variant a concern, but we need to look around the corner to the next mutation of the disease.” One heated moment in the hearing - a pointed exchange between Republican Senator Rand Paul and Fauci - in which Senator Paul accused the infectious disease expert of lying about the National Institutes of Health providing funding for research at China's Wuhan Institute of Virology.

The Senator from Kentucky, who has sparred with Fauci during several pandemic-related hearings, alleged that the research may have played a role in developing the novel coronavirus at the Wuhan Lab.

Paul: “As you are aware, it is a crime to lie to Congress.

Section one zero zero one of the US Criminal Code creates a felony and a five year penalty for lying to Congress.” (flash) Fauci: “Senator Paul, I have never lied before the Congress and I do not retract that statement (flash) you do not know what you are talking about, quite frankly.

And I want to say that officially (flash) you are implying that what we did was responsible for the deaths of individuals, I totally resent that, and if anybody is lying here Senator, it is you.” The origin of the novel coronavirus has become a heated partisan issue in the United States, with Republicans urging further inquiries into whether it leaked from a lab.

President Biden in late May called on aides to investigate the origins of the virus and to report back to him within 90 days.