It was already widely known that wild measles virus can cause colitis so theoretically a live virus vaccine like MMR could do the same. (3 and 4)
A further three children with regressive autism were found to have measles vaccine virus in their cerebrospinal fluid after a spinal tap had been performed.
"In light of encephalopathy presenting as autistic regression (autistic encephalopathy, AE) closely following measles-mumps rubella (MMR) vaccination, three children underwent cerebrospinal fluid (CSF) assessments including studies for measles virus (MV). All three children had concomitant onset of gastrointestinal (GI) symptoms and had already had MV genomic RNA detected ... None of the cases or controls had a history of measles exposure other than MMR vaccination."
They thought this raised the possibility of virally-driven brain damage resulting in some cases of regressive autism. (5)
Early life exposure to mercury and other metals, followed by exposure to live viruses could potentially tip the child into autoimmunity.
Some vaccine viruses are cultured on fetal tissue cells obtained from aborted fetuses. Although it isn’t an added ingredient, trace amounts of fetal DNA will remain in the vaccine. Vaccines that contain fetal DNA include MMR, varicella, some Hepatitis B vaccines and Hepatitis A.
Children can produce antibodies to all components of vaccines and not merely the viruses or bacteria, so injecting fetal DNA can cause the child to develop antibodies to human tissue, another possible factor in autism.
Doctors in Portugal blood tested 171 autistic patients, 191 parents and 54 healthy people and found that the autistic patients had high levels of non-inherited antibodies to their own brain tissue. (6)
Spikes in the incidence of autism were seen in the UK in 1988 when the MMR was introduced and in the United States in 1995 when varicella vaccine was introduced, pointing to a possible link with fetal tissue in vaccines. (1)
It is important that research into the childhood vaccination schedule be continued, particularly while rates of autism show no sign of slowing down.