The Last Week Tonight host devoted almost the entire episode to discussing vaccine hesitancy and he also revealed he had received his second shot and suffered no major side effects.

Rogan caused considerable controversy when he told listeners he didn’t think that “young, healthy” people needed to get the vaccine. He later walked back the comments following reaction from Dr. Anthony Fauci, among others.

“Our best way out of this mess long term is clearly vaccines,” Oliver said.

“These vaccines can save not just your life but the lives of people around you, and it’s genuinely dispiriting that just a few months into the vaccine rollout we are already at this point,” he said, referring to people refusing to be vaccinated.

“And the problem is, for the Coronavirus, the herd immunity threshold is thought to be between 70 and 90 percent of the population, but a survey found that while 60 percent of American adults have got—or want to get—the vaccine, and about 18 percent say ‘maybe,’ and 22 percent say ’no.’”

He was referring to a CBS News/YouGov poll published on April 26.

Oliver addressed Rogan’s remarks about young people and the vaccine, urging viewers not to listen to the podcaster on the issue.

“If you’re thinking, Yeah, I’m not sure I’ll need it. Joe Rogan says I’m probably fine. It is true: You might not get seriously sick from COVID - or indeed sick at all - but you could still inadvertently pass it to someone who could then die,” Oliver said.

“And before you say, ‘Well, vulnerable people should just get vaccinated then,’ the vaccines are only 95 percent effective… so they’ll probably be OK, but maybe not,” he went on.

“Also, the more the virus circulates, the likelier we’ll see mutations that make it more dangerous, possibly helping it to evade the vaccine completely, putting us all the way back to square one, so get the f*cking vaccine!”

“Stop listening to what Joe Rogan tells you, he’s a ‘f*cking moron’—and those are his words, not mine,” Oliver said.

Rogan had referred to himself using the insult when he clarified his comments about vaccines on Thursday.

“I’m not a doctor, I’m a f*cking moron, and I’m a cage-fighting commentator who’s a dirty stand-up comedian,” Rogan said. “I’m not a respected source of information, even for me.”

Oliver ended the segment by urging viewers to help convince those in their lives who are skeptical of vaccines to accept them, without judging them for having questions or doubts.

Newsweek has asked Joe Rogan for comment.