The earliest report of smallpox oral vaccination by Bahā' al-Dawlah Rāzī in the 16th century.

Smallpox is one of the viral and contagious diseases that were always talked about and deadly epidemics that killed many people for many centuries. Through the analysis of historical and textual material, this paper seeks to investigate the smallpox eradication process. It starts with a brief history of smallpox before listing the common methods of eradicating the illness throughout the 16th century. There was a type of traditional oral smallpox vaccination, reported by Bahā' al-Dawlah Rāzī, a Persian physician in his book, Khulāsāt al-Tajārib (The Summary of Experiences). This method could be considered the earliest remained report of practical solution to prevent smallpox; at least 3 centuries earlies than smallpox vaccination by Edward Jenner.