In August 2014, anti-vaccine activists Brian Hooker and Andrew Wakefield released a video of recorded phone conversations with Dr. William Thompson, a researcher at the Centers for Disease Control and Prevention (CDC). In the recordings, Dr. Thompson claims to have evidence that the CDC altered the rules of data collection for a study in order to omit data which would have shown African American boys had a greatly higher incidence of autism after MMR (measles-mumps-rubella) vaccination. The collection of materials below explain why this claim was not credible.