evidence: FULL CLAIM: Vaccines contain unhealthy amounts of aluminum and heavy metals which cause autism; infant mortality and autism rates in Japan are lower than those in the U.S. because Japan stopped requiring childhood vaccinations; rise in autism rates in the U.S. is due to rise in childhood vaccines; children's underdeveloped immune systems can’t handle the number of vaccines they receive [...] Aluminum levels in vaccines are safe and don’t cause autism [...] As we reported in a previous claim review, infants receive approximately 4.4 milligrams of aluminum via vaccines administered in the first six months of life. This is in the form of aluminum-containing salts that act as adjuvants to enhance the immune response to vaccination, which have been used in vaccines for more than 70 years.