In 1975 Japan raised the minimum age for infant vaccinations to 2 years. As a result, SIDS (Sudden Infant Death Syndrome, or, crib death) and infant convulsions virtually disappeared. In the 80’s, Japan lowered the minimum age back down to 3 months and the rate of SIDS returned to previous levels. (ii)
In an Australian study, a group of recruits were immunized for Rubella, and all produced the expected antibodies. When later exposed to the disease, 80% of the recruits contracted it. (iii)






