Though it may come as a surprise to his followers, Donald Trump is triple vaccinated.

The former US president confirmed his vaccination status during a new talk with Bill O'Reilly. The Trump-supporting crowd, however, didn't take kindly to the news that Trump took the COVID-19 booster shot.

Donald Trump booed by fans over COVID booster news

Trump and O'Reilly are on a tour that visited Dallas on Monday. During the show, O'Reilly stated: "Both the president and I are vaxxed." He then asked Trump: "Did you get the booster?"

Trump hesitated for a split second but replied firmly: "Yes." In video of the moment, a contingent of the crowd is heard jeering after Trump's answer.

Trump heard the boos, began waving his hand, and called out: "Don't, don't, don't, don't..." He then pointed and remarked: "There's a very tiny group over there."

Trump's moment with the crowd is seen at the end of the video above. It came after the disgraced ex-president encouraged his supporters to join him in "taking credit" for creating the vaccine that saved "tens of millions of lives."

Afterward, O'Reilly also revealed that he had to reassure Trump about discussing his vaccination status publicly.

According to Business Insider, O'Reilly said he told Trump it was "good" for him to have that moment of "truth" and to "take credit" for the vaccine, even if segments of his fanbase are anti-vax.

O'Reilly, the ex-Fox News host who left the network in 2017 after a misconduct scandal, wrapped up a touring show with Trump this week.

Despite his role in the Jan. 6 riot, Trump remains eligible to run for president in 2024, though he has yet to confirm if he'll do so.