Baby monkeys that were given vaccines according to the U.S. vaccination schedule had abnormalities in the region of the brain affecting social and emotional development

This study was designed to investigate structural and functional changes in the developing infant primate brain following administration of U.S. pediatric vaccines according to the recommended childhood schedule.

In this study, 12 male infant rhesus macaques received the complete, age-adjusted childhood vaccine regimen. Four additional macaques, the control group, received saline injections. MRI and PET scans at 4 and 6 months of age were obtained from 9 of the vaccinated and 2 of the control animals.

The MMR, DTaP, and Hib-vaccinated primates had significantly altered amygdala growth (associated with the development of social and emotional behavior) compared to the unvaccinated primates.

The vaccinated primates had a significant increase in total brain volume. An accelerated increase in total brain volume between 6 and 14 months of age is a consistent finding for many children with autism.

Findings in this study suggest that vaccines may be associated with significant disturbances in brain growth and development.