CNN  — 

Former President Donald Trump was booed by a portion of an audience in Dallas on Sunday when he said he had received a Covid-19 booster shot, according to video of the closed press event that was shared on social media.

The comments by Trump – who, despite championing his administration’s efforts to develop Covid vaccines, rarely discusses his own vaccination and has largely declined to encourage others to get it – came during a stop of his tour with former Fox News host Bill O’Reilly.

According to video tweeted by O’Reilly’s “No Spin News,” the former Fox News host says, “Both the President and I are vaxxed” and then asks Trump, “Did you get the booster?”

“Yes,” Trump says to a smattering of boos in the audience. “Don’t, don’t, don’t, don’t, don’t,” Trump says in the video, seemingly trying to quiet the boos. “That’s all right, it’s a very tiny group over there.”

CNN has reached out to a Trump spokesperson for more details on the former President’s decision to get the booster shot.

In a longer video later tweeted by O’Reilly’s site, Trump warns supporters that they are “playing right into their hands” when they dismiss the vaccines and don’t take credit for them.

“Look, we did something that was historic, we saved tens of millions of lives worldwide. We, together, all of us, not me,” Trump says in the video, which comes right before Trump receives the smattering of boos.

He goes on to say that Covid-19 was going to “ravage the country far beyond what it is right now” if the vaccines had not been developed.

“Take credit for it. Take credit for it. It’s great. What we’ve done is historic. Don’t let them take it away. Don’t take it away from ourselves,” Trump says. “You are playing right into their hands when you sort of like, ‘oh, the vaccine.’ If you don’t want to take it, you shouldn’t be forced to take it. No mandates. But take credit, because we saved tens of millions of lives. Take credit. Don’t let them take that away from you.”

Unvaccinated people face a 10 times greater risk of testing positive and 20 times greater risk of dying from Covid-19 than fully vaccinated people who have also received a booster, according to data published recently by the US Centers for Disease Control and Prevention.

The CDC data – which assesses data through October – suggests the gap in risk between unvaccinated people and those with a booster is even larger than it is between unvaccinated people and those who are fully vaccinated with their initial series. Unvaccinated people face a five times greater risk of testing positive for Covid-19 and 14 times greater risk of dying from Covid-19 than fully vaccinated people do, according to the CDC data.

Trump, who contracted Covid as president, received his first Covid-19 vaccination out of view of the press before leaving office. CNN reported months later that his vaccination was not recorded by official photographers or videographers, according to a person familiar with the matter. And Trump did not participate in a Covid-19 public service announcement that featured all other living former presidents.

Dr. Anthony Fauci, the nation’s top infectious disease specialist, praised Trump’s decision to publicize his booster shot during an appearance on CNN’s “New Day” Tuesday morning.

“I’m very pleased that he did say that and come out publicly and say that he has been vaccinated and boosted,” Fauci said. “But to get booed for saying that just tells you about the extraordinary divisiveness we have going into this public health issue, which should be devoid of divisiveness. It should just be focusing on what the public health principles are.”

Trump had said in a Wall Street Journal interview that published in September that he was unlikely to get the booster shot, saying that he felt like he was “in good shape from that standpoint” and “probably won’t” get the booster.

“I’ll look at stuff later on,” he added. “I’m not against it, but it’s probably not for me.”

This is not the first time Trump has been met with boos when speaking about vaccines.

“I believe totally in your freedoms. I do. You’ve got to do what you have to do. But I recommend, take the vaccines. I did it. It’s good. Take the vaccines,” Trump said at an event in Alabama in August.

Some in the audience responded by booing the statement.

“No, that’s OK. That’s all right,” Trump said, seemingly acknowledging the boos. “You got your freedoms, but I happened to take the vaccine. If it doesn’t work, you’ll be the first to know, OK?”

This story has been updated with additional information.

CNN’s Veronica Stracqualursi contributed to this report.