President Donald Trump criticized former Vice President Joe Biden and his running mate, Sen. Kamala Harris (D-CA), on Monday for publicly undermining a future coronavirus vaccine.

In a press conference at the White House, Trump called on Harris and Biden to “immediately apologize for the reckless anti-vaccine rhetoric.”

Biden questioned the safety of a potential coronavirus vaccine during an interview with Florida’s WKMG News 6 last Thursday.

“Who’s going to take the shot? Are you going to be the first one to say, ‘Sign me up,’ they now say it’s OK?” Biden asked.

Harris also cast doubt on a future vaccine in an interview on Sunday, calling it “an issue for us all.”

“I would not trust Donald Trump, and it would have to be a credible source of information that talks about the efficacy and the reliability of whatever he’s talking about,” she said.

Trump dismissed Biden and Harris’s comments as political rhetoric that was “endangering lives.”

“It undermines science,” Trump said, adding that “they’ll say anything and it’s so dangerous for our country.”

Last week, Trump indicated that a vaccine for the virus could be developed as soon as October despite most experts predicting a vaccine development by the end of 2020. But he promised that the future coronavirus vaccine would be safe despite its rapid testing and development process.

“The vaccine will be very safe, very effective, and it will be delivered very soon. You could have a big surprise coming up,” he said.