White House coronavirus task force coordinator Deborah Birx said on ABC’s “This Week” Sunday that social distancing is “absolutely critical,” and that if Americans can’t maintain at least six feet from other people while gathering outside, they “must wear a mask.”

Why it matters: As states have begun to reopen, many Americans have flocked to beaches and outdoor restaurants in large numbers to celebrate Memorial Day weekend. Birx warned that people could be spreading the virus unknowingly, and asked those with co-morbidities to remain sheltered in place.

What they’re saying: “We’ve made it clear that there’s asymptomatic spread, and that means that people are spreading the virus unknowingly,” Birx said. “And this is unusual in the case of respiratory diseases in many cases.”