Dear O. m.
This is a very well known side effect of many vaccines. Research came out about 8 years ago from a British study believing that if a child has slight allergies to chicken eggs that this could cause serious flu vaccine side effects such a stuttering. The same study discovered that other children may be sensitive to the mercury (thimerosal) aluminum or formaldehyde. This study was supposed to lead to the removal of the 3 chemicals in vaccines but unfortunate nothing has happened yet. I will look for the study and post it.
Many mothers have used a product called Vaxtox to clear these side effects and for man it has worked. Some children did not clear the side effect entirely but improved greatly. The manufacture of Vaxtox believes if the product is used ASAP after the vaccines that the results would be more successful.