Criticism from the medical community and pressure from other filmmakers with work screening at this year's Tribeca Film Festival forced co-founder Robert De Niro to pull the movie, "Vaxxed: From Cover Up to Catastrophe," from the documentary line-up. De Niro's decision came a day after he defended the anti-vaccine film's screening.

"Vaxxed" was directed and co-written by Andrew Wakefield, an anti-vaccination activist and the author behind a discredited study that linked vaccines to autism. The study was published in 1998 in the British medical journal, The Lancet, and then retracted in 2010. Britain's General Medical Council also revoked Wakefield's medical license for ethical violations and failing to disclose financial conflicts of interest.

On Friday, De Niro issued a statement defending the film's screening. It was the first time the 72-year-old actor-director had ever involved himself in the programming of the festival that he helped found in 2002. The issue of autism is personal to him and his wife, Grace Hightower De Niro, who have a child with autism, but he noted that he was "not personally endorsing the film" and is not "anti-vaccination."

"We believe it is critical that all of the issues surrounding the causes of autism be openly discussed and examined. In the 15 years since the Tribeca Film Festival was founded, I have never asked for a film to be screened or gotten involved in the programming. However, this is very personal to me and my family and I want there to be a discussion, which is why we will be screening VAXXED," he said.

"Vaxxed" was set to screen on April 24, followed by a discussion with the director Wakefield and subjects of the film. Less than 24 hours after his first statement, De Niro changed his mind and pulled the film from the schedule.

"My intent in screening this film was to provide an opportunity for conversation around an issue that is deeply personal to me and my family," De Niro stated. "But after reviewing it over the past few days with the Tribeca Film Festival team and other from the scientific community, we do not believe it contributes to or furthers the discussion I had hope for."

Scientists and filmmakers alike commended De Niro and the festival for their decision to pull "Vaxxed." But the exposure given to the film during this controversy is still troubling for some.

"It gave these fraudulent ideas a face and a position and an energy that many of us thought they didn't deserve," said Dr. William Schaffner, a professor of preventive medicine at the Vanderbilt University School of Medicine. "We're all for ongoing reasonable debate and discussion, but these are ideas that have been proven to be incorrect many, many, many times over the past 15 years."

Penny Lane, whose documentary "Our Nixon" will screen at this year's festival, posted an open letter in Filmmaker Magazine on Thursday that argued the screening of "Vaxxed" "threatens the credibility of not just the other filmmakers in your doc slate, but the field in general." Lane described the film's cancellation as "momentous and significant" but still had reservations about its inclusion in the first place.

"This wasn't about exposure; it was about credibility," she said. "The kind of credibility an A-list film festival, or any important, respected gatekeeper, can give you, especially once you've been discredited by everyone else."

The Tribeca Film Festival will start on April 13.