ARI SHAPIRO, HOST:
We learned a lot this week about the highly contagious delta variant of the coronavirus, and in response, corporate and government leaders around the country dramatically shifted their response to this phase of the pandemic. So we're going to begin this Friday by taking stock of what has changed. In a moment, we'll talk with the nation's top infectious disease doctor. Here's what Anthony Fauci said nine days ago.
(SOUNDBITE OF ARCHIVED RECORDING)
ANTHONY FAUCI: Although the CDC still has a broad recommendation that if you are fully vaccinated, you do not need to wear a mask, indoor and outdoor, they make it very clear that they yield in many respects to the local authorities depending upon the situation on the ground.
AILSA CHANG, HOST:
Six days later, this past Tuesday, the situation on the ground had changed enough for the CDC to change course. The agency's latest mask guidelines advise fully vaccinated Americans to mask up indoors in areas where the coronavirus is circulating widely. This is how Dr. Fauci explained the shifting guidance to All Things Considered on Tuesday.
(SOUNDBITE OF ARCHIVED NPR BROADCAST)
FAUCI: The virus has changed. We are dealing with a different virus now. This is not the original virus.
SHAPIRO: By Wednesday, states from California to New York had announced new vaccine requirements for workers. And a new study from Israel suggested that some vaccinated people might be at risk for long COVID symptoms. Here's Saad Omer, a vaccine expert at Yale.
(SOUNDBITE OF ARCHIVED NPR BROADCAST)
SAAD OMER: You can imagine your vaccine providing a bit of a forcefield, but that's not the case anymore. It's still pretty strong armor, but it's penetrable armor.
SHAPIRO: He told NPR that while vaccines are not perfect, they are still really good at preventing serious illness. And that's part of the appeal President Joe Biden made on Thursday when he announced vaccine and testing requirements for 4 million federal workers and contractors.
(SOUNDBITE OF ARCHIVED RECORDING)
PRESIDENT JOE BIDEN: If, in fact, you're unvaccinated, you present a problem - to yourself, to your family and to those with whom you work. Transcript provided by NPR, Copyright NPR.