Vaxx: From Cover-Up To Catastrophe, a controversial documentary that links measles, mumps, rubella vaccine to autism is no longer streaming on Amazon Prime.

The move is a response to a letter sent to CEO Jeff Bezos by Democratic Representative Adam Schiff of the 28th District of California. In the letter, he demanded to know what the company is doing to prevent the spread of misinformation about vaccines.

Two other documentaries titled Man Made Epidemic and Shoot 'Em Up: The Truth About Vaccines seem to have been removed from the streaming service as of Friday, March 1.

Jeff Bezos Receives Criticism For Amazon's Anti-Vaccine Content

Last week, Schiff published a letter addressed to Bezos discussing the growing anti-vaccine sentiment around the world as a threat to public health. The lawmaker noted that Amazon might be recommending products and content that further discourage parents from vaccinating their children.

"There is strong evidence to suggest that at least part of the source of this trend is the degree to which medically inaccurate information about vaccines surface on the websites where many Americans get their information, among them Amazon," the letter read. "As the largest online marketplace in the world, Amazon is in a unique position to shape consumption."

So far, Amazon has neither issued a response to Rep. Schiff's criticism nor confirmed the documentary's removal from the streaming platform. However, Vaxxed: From Cover-Up to Catastrophe, as well as several other anti-vaccine documentaries and books, are still available for purchase from the e-commerce giant.

Rep. Schiff also urged Facebook and Google to stop recommending content that has anti-vaccine messages.

Vaccine Does Not Cause Autism

Vaxxed: From Cover-Up to Catastrophe is based on a 1998 research by Andrew Wakefield, who also directed the documentary, alleging that the MMR vaccine causes autism. The British doctor not only later retracted the research, but his findings have been debunked by several other studies.

In 2015, researchers examined over 95,000 children across the United States and found no link between MMR vaccine and autism.

Wakefield has also been stripped of his medical license for ethics violations. Journalist Brian Deer discovered in 2011 that Wakefield pocketed over $75,000 while trying to prove the link between vaccines and autism. Moreover, Wakefield proposed the establishment of a company that will "reap huge returns from molecular viral diagnostic tests for autism."

The documentary had the backing of actor Robert De Niro, who has an autistic son and later withdrew his support. It was barred from being screened during the Tribeca Film Festival in 2016.