Not backing down! Jimmy Kimmel made his stance on the anti-vaccination movement perfectly clear last week when he brought doctors on to squash the dubious theories, and he just took it a step further on Monday evening's episode of Jimmy Kimmel Live!

"Last week on the show, I spoke about something I've been thinking about lately, which is childhood vaccinations," Kimmel, 47, began on Monday, March 2. "My daughter's almost 8 months old and she got her booster shot this morning. I've become more aware of the fact that some parents don't believe in vaccinating their kids, which is something that the overwhelming majority of the medical community recommends."

"I got a group of real doctors together to do a public service announcement urging parents to vaccinate, and wow did this make some people mad," the funnyman continued. 

He then went on to read tweets from members of the movement he called him a "pathetic f--king human being," a "f--king piece of s--t," and insinuated that he was being paid off by pharmaceutical corporations. 

"Some of these people are demanding that I apologize, which I of course will not do," Kimmel said. "A lot of these groups are insisting that I present both sides of the argument, and I'm not gonna do that either well, for the same reason that I wouldn't present both sides if a group of people decided that pancakes make you gay — they don't and there's no point in discussing it."

"But in the interest of fairness, we sent our community activist team, Jack and Becky, out to the street," he added. "Jack and Becky care a lot and here they are now, anti-vaccination crusaders." 

Kimmel then introduced a clip of the two fake activists on the streets of California, pushing their agenda of a "child's right to choose" whether or not they get vaccinated. Watch the pedestrian's uproarious reactions to their campaign in the video above!