Health Secretary Robert F. Kennedy Jr., who has often linked vaccines to the neurodevelopmental disorder autism, said Thursday that his agency will know by September the reason behind its rising prevalence in the U.S.

During a Cabinet meeting attended by President Donald Trump at the White House, RFK Jr. added, “At your direction, we've launched a massive testing and research effort that's going to involve hundreds of scientists from around the world.”

“By September, we will know what has caused the autism epidemic, and we will be able to eliminate those exposures,” he added.

His remarks follow the CDC’s recent plans to run a study to investigate whether vaccines cause autism, a claim debunked by numerous peer-reviewed studies, including a 2015 research published in JAMA that evaluated the health records of more than 95K children.

Vaccine makers: GSK (NYSE:GSK), Merck (NYSE:MRK), Moderna (MRNA), BioNTech (BNTX), Pfizer (NYSE:PFE), Novavax (NVAX), and Sanofi (NASDAQ:SNY).