Dr. Anthony Fauci cautioned that it is too soon to return to sports stadiums, which have been filled with people not wearing masks as the Delta variety spreads—despite vaccines demonstrating good protection against serious infection.

“I don’t think it’s smart,” the White House chief medical adviser told CNN earlier this week.

“Outdoors is always better than indoors, but even when you have such a congregate setting of people close together,” Fauci added.

Fans are coming to the venues, although about 136,000 new cases are reported daily in the United States, according to the latest seven-day average from the Centers for Disease Control and Prevention.

The CDC defines fully vaccinated as two weeks after the second dosage of a Pfizer or Moderna vaccine or two weeks after a Johnson & Johnson single-dose vaccine, according to the New York Post.

Fauci made his remarks just days before the highly anticipated 2021 football season began on Thursday, Sept. 9.

The league’s executive vice president of club business and events, Peter O’Reilly, said he doesn’t expect a drop in attendance this season—and that it’s safe to go to the games.

“We and our clubs are in daily and regular conversations with local and state authorities, but as we sit here right now, we don’t anticipate any reduction in capacity this year,” O’Reilly said in the league’s last briefing.

“We really feel good about where we stand, given the vaccination rates across the country, and feel as though we will be able to move through the season,” he continued.

“Obviously, we don’t take anything for granted. We work closely on all of our protocols, working with and under the guidance of those state and local authorities.

“As we sit here today, all 30 stadiums are able to be at full capacity and that’s how we expect to go through the season in lockstep with those local and state authorities.”

Some stadiums were packed to capacity during college football’s first full weekend.

“While people are still getting sick, people aren’t dying at the same rate, according to the statistics. That’s the key,” Dr. Rand McLain, chief medical officer of Live Cell Research Health, told the Associated Press.

“You go back to where it started, hospitals were loading up and an inordinate amount of people were dying,” he said.

“We’re past that now, at least at this time, though we have the Delta variant and the Mu variant beating the vaccines. From there, being outside is a huge plus. You’re not seeing the transmission when there’s a breeze blowing.”

The CDC recommends that all Americans, including the completely vaccinated, wear masks outside if they cannot practice social distancing.

Dr. Iahn Gonsenhauser, the chief quality and patient safety officer at Ohio State University Wexner Medical Center, agreed with the top infectious disease specialist.

“If you want to minimize your risk as much as you can, going to a sporting event is not the right choice,” he told CNBC.