Dr. Anthony Fauci spoke out on Sunday to issue a chilling warning that the worst is yet to come with the coronavirus pandemic.

Fauci, who has long been a member of the White House COVID-19 task force, told CNN that Joe Biden was correct in warning that cases were expected to surge due to families gathering for the holiday season.

“As we have gone from the late fall to the early winter, the numbers really are quite troubling,” Fauci said. “With the hospitalizations over 120,000, we really are a critical stage.”

Referring to Christmas gatherings, Fauci said, “Even though we advise not to, it’s going to happen.”

However, Fauci went on to add that as vaccines are distributed over the course of the coming months, U.S. health experts should see the general population reach significant herd immunity by the end of the summer.

“I think that’s going to probably be by the middle to the end of the summer, so … I hope that, by the time we get to the fall, we will reach that critical percentage of people,” Fauci said.

This came after Biden spoke out last Tuesday to warn Americans against gathering for Christmas.

“Experts say things will get worse not withstanding the vaccine,” Biden said in a press conference. “We’re averaging a death rate of close to 3,000 a day. That means we will lose tens of thousands of more lives in the months to come, and the vaccine won’t be able to stop that. So we still have to remain vigilant.”

Fauci, who turned 80 last week, had said that he would not even be seeing his own adult children for Christmas due to COVID-19.

“I really feel strongly that I need to practice what I preach to the country,” he said. “Although I would love very much to have my children, who live in different parts of the country, [to] come in together and have a celebration for my birthday and Christmas, I don’t think that’s the prudent thing to do, so I’ll be having a quiet dinner with my wife, and we’ll Zoom in the children.”