Another theory one may have is that the ingredients in a vaccine may be harmful. Some scientist have even tried linking one of the ingredients, thimerosal, is linked to diseases such as autism. Thimerosal can be found in the flu vaccine, which is the most common vaccine given to both children, and adults. Aluminum is said to be found in some vaccines as well. An excessive amount of aluminum may be extremely harmful to one’s body, and may even put one more at risk to develop cancer. Formaldehyde, is linked to nervous system depression and is also a key ingredient for some vaccinations. Another ingredient that may be harmful to one’s body includes Glutaraldehyde which is found in the DTap vaccine, and can cause asthma along with other respiratory