The 1998 study that started the vaccine scare was based on fake data and was completely retracted.

In 1998, Andrew Wakefield published a paper claiming the MMR vaccine could cause autism. But the study only looked at twelve children. Later, investigators found that Wakefield had lied, changed the children's medical records, and failed to mention he was being paid by lawyers who wanted to sue vaccine companies. The journal that published the paper completely retracted it in 2010. Wakefield was found guilty of scientific misconduct and lost his medical license. The study was a total fraud.