• Half of all American adults have received at least one dose of the coronavirus vaccine, and of those age 65 and older, 81% have received one dose or more, according to the Centers for Disease Control and Prevention.
• “I worry... that we're rapidly transitioning our country from a supply issue, a scarcity issue with vaccines, to a demand issue,” said Dr. Carlos Del Rio. “I will tell you the most reluctant communities are primarily white evangelicals and we really need to get out to those communities to vaccinate them.” 
• “When we can get community transmission down to below ten cases per 100,000 population, I think wearing masks outdoors is not going to be necessary,” said Del Rio.

Dr. Carlos Del Rio said that U.S. Covid cases could drop dramatically going into May, as long as the U.S. continues to vaccinate aggressively and convinces reluctant communities to get vaccinated. 

"I worry... that we're rapidly transitioning our country from a supply issue, a scarcity issue with vaccines, to a demand issue," said Del Rio. "I will tell you the most reluctant communities are primarily white evangelicals and we really need to get out to those communities to vaccinate them." 

There are about 41 million white evangelical adults in the U.S., and about 45% said in late February that they would not get vaccinated against Covid-19, making them among the least likely demographic group to do so, according to the Pew Research Center. 

Half of all American adults have received at least one dose of a coronavirus vaccine. Of those age 65 and older, 81% have received one dose or more, and about two-thirds are fully vaccinated, according to the Centers for Disease Control and Prevention. 

Del Rio, a professor of medicine specializing in infectious diseases at Emory University School of Medicine, told CNBC's "The News with Shepard Smith" that the U.S. may be able to follow Israel's lead and lift outdoor masking requirements if community transmission drops. 

"When we can get community transmission down to below ten cases per 100,000 population, I think wearing masks outdoors is not going to be necessary," said Del Rio. 

Host Shepard Smith also asked Del Rio about Texas and those who point to the state as an example of successfully lifting mask mandates. The average daily Covid cases are down 41% in Texas since Gov. Greg Abbott lifted the mask mandate 40 days ago, according to Johns Hopkins University. Del Rio noted that there's still a lot of unknowns about Covid and that states should still proceed with caution when it comes to lifting Covid restrictions. 

"I think sometimes we wonder whether a place like Texas is good or lucky, and I think it's more lucky than good, quite frankly," said Del Rio.  

CDC Director Dr. Rochelle Walensky has warned that Americans should still have their guard up when it comes to Covid.