However, as shown by the now-retracted small case series in Lancet connecting MMR vaccinations with autism, small case series do not replace the value of clinical trials, with rare exception, when considering impacts to widespread, common clinical practice.
We summarize the key evidence on some of the main current vaccine safety controversies in the United States, including: 1) MMR vaccine and autism; 2) thimerosal, a mercury-based vaccine preservative, and the risk of neurodevelopmental disorders; 3) vaccine-induced Guillain-Barré Syndrome (GBS); 4) vaccine-induced autoimmune diseases; 5) safety of HPV vaccine; 6) aluminum adjuvant-induced autoimmune diseases and other disorders; and 7) too many vaccines given early in life predisposing children to health and developmental problems.
Leukocyte preparations from children with documented evidence of MMR vaccination and confirmed diagnosis of autism were examined by several assays designed to target multiple regions of the measles virus genome sequence.
Additionally, a new syndrome has been reported in children with autism who exhibited developmental regression and gastrointestinal symptoms (autistic enterocolitis), in some cases soon after MMR vaccine.