JUDY WOODRUFF: The White House is issuing urgent calls to action tonight in the face of COVID-19's latest assault. The appeals come amid talk of reimposing restrictions. Amna Nawaz begins our coverage.
AMNA NAWAZ: The Biden team today issued a sober warning today and an urgent call for far more vaccinations, as the number of Delta-related infections is rising around the country. Dr. Rochelle Walensky is the director of the Centers for Disease Control and Prevention.
DR. ROCHELLE WALENSKY, CDC Director: We are yet at another pivotal moment in this pandemic, with cases rising again and some hospitals reaching their capacity in some areas. We need to come together as one nation. The Delta variant is more aggressive and much more transmissible than previously circulating strains. It is one of the most infectious respiratory viruses we know of and that I have seen in my 20-year career.
AMNA NAWAZ: As new cases of COVID surge, the Biden administration is maintaining its mask guidance.
JEN PSAKI, White House Press Secretary: There has been no decision to change our mask guidelines. Any decisions about public health would be driven by the CDC. But, of course, we are engaged with public health experts and the CDC about how to continue to attack the virus. And we have never said that battle is over. It's still ongoing.
AMNA NAWAZ: The seven-day average of new cases in the U.S. is up 53 percent; 83 percent of cases are now comprised of the Delta variant. And three states, Florida, Texas, and Missouri, account for 40 percent of all new cases nationwide. Hospitalizations and deaths are still a fraction of what they were at their peak, due to vaccinations, which experts say also protect against the Delta strain. Last night, President Biden urged the public to get inoculated at a CNN town hall.
JOE BIDEN, President of the United States: If you're vaccinated, you're not going to be hospitalized, you're not going to be in an ICU unit, and you're not going to die. So, it's gigantically important that you act like -- we all act like Americans who care about our fellow Americans.
AMNA NAWAZ: As U.S. officials attempt to ramp up the vaccine effort, the effort to investigate the virus' origins also continues. On Capitol Hill, some Republican lawmakers also spoke of the need for vaccines.