Fluoridation of community water supplies is considered as one of the ten great public health measures of the twentieth century. Immunization against infectious diseases represents one of science’s greatest triumphs. Many of the epidemic diseases of the past are now controlled and all but eliminated in developed countries. Both these measures are mired in controversies and are opposed by small minority vocal groups around the world. These elements delayed eradication of smallpox by over a century which resulted in millions of lives and disfigurement of millions more. The same opposition groups are making parents refuse vaccination of their children resulting in reemergence of dreaded diseases of the past. This book narrates the opposition to fluoridation as well as vaccination and makes a plea that opposition to fluoridation and vaccination should be met effectively, otherwise mistakes of smallpox vaccination are going to be repeated. This book is the outcome of long discussions while traveling in the endemic areas of fluorosis, attending on cases suffering from fluorosis and infectious diseases in hospitals and participating in animal experimental studies.