In 1974 there was an epidemic of meningitis in Brazil. Dr. Francisco Eizayaga gave 18,640 children the homeoprophylactic remedy called meningococcinum. Only four cases of the illness were found. In the untreated group of 6,340 children, there were thirty-two cases found.
The study was repeated in 1988 with individuals between the ages of 0-20 years old. In the group of 65,826 treated with homeoprophylaxis, only one case of meningitis was reported in the six months following the study. Of the 25,532 untreated individuals, seven cases were reported during the same time. Twelve months later, the follow-up reported three cases in the protected group and thirteen cases in the unprotected group. This reflects eighteen times the disease attack rate in the untreated group.
Statistical analysis demonstrated homeoprophylaxis displayed 95% protection from contracting meningitis in children under six months old and 91% protection in children over 12 months old. There were no deaths, no adverse effects, and no side effects from the use of homeoprophylaxis.