He added that he hadn't yet "fully explored" the fierce backlash against the documentary "and I will".
De Niro, who has an 18-year-old Elliot son with autism, said he had hoped that screening the film could have started a 'discussion' about the alleged link between the vaccine and autism.
"There's a lot of things that are not said. Nobody seems to want to address that, or they say they've addressed it and it's a closed issue. But it doesn't seem to be because there are many people who say they saw their kid change overnight.
"My wife says that (is what happened to my son). I don't remember. But my child is autistic. I, as a parent, of a child who has autism, I'm concerned, I want to know the truth."
De Niro also suggested that people should watch another documentary, Trace Amounts, which focuses on the now disproved link between autism and vaccines. "There's a lot of information about things that are happening with the CDC, the pharmaceutical companies, there's a lot of things that are not said."
De Niro admitted he was "not too sure" about the disgraced former British doctor, Andrew Wakefield, who is at the centre of the documentary. But he wanted to help overcome the reluctance to talk about the issue, both in the scientific community and in the general public.
He felt that people were trying to 'shut down' discussions around vaccines and autism. "There's more to this than meets the eye, believe me. There's something that people aren't addressing. And for me to get so upset here, on the Today show, with you guys, means there's something there."
The actor said he simply had not anticipated the "knee jerk" reaction from filmmakers - many of whom had threatened to pull out the festival.
"Part of me does (regret pulling it), and part of me says let it go for now and I'll deal with it later in another way. Because I didn't want the festival to be affected."
De Niro told the presenters he was skeptical of the scientific community's findings that there is no link between the vaccine and autism. "I believe it's much more complicated than that. I'm not a scientist but i know because I've seen so much reaction. I'm not anti-vaccine, but I'm pro-safe vaccine."
He went onto compare the reactions of some children to medications such as penicillin - and claimed it could be the same with vaccines. He even questioned the rise in cases of preventable diseases, such as measles, across the country since the MMR controversy.
"There's a kind of hysteria, a knee jerk reaction. Everybody should have choice whether to take vaccines or not. But it does benefit big drug companies."
The actor and producer had first announced he would be screening the documentary at the festival in a personal statement. "Grace and I have a child with autism and we believe it is critical that all of the issues surrounding the causes of autism be openly discussed and examined," he said, referring to his wife of 18 years, Grace Hightower.
"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. I am not personally endorsing the film, nor am I anti-vaccination; I am only providing the opportunity for a conversation around the issue."
However, he later said that after reviewing the film alongside Tribeca organizers and members of the scientific community, the decision to screen the movie had been reversed. "The Festival doesn't seek to avoid or shy away from controversy. However, we have concerns with certain things in this film that we feel prevent us from presenting it in the Festival program. We have decided to remove it from our schedule."
- Daily Mail
