English: This historic 1967 photograph features (left to right) Dr. Ronald R. Roberto (EIS 1962), Prince Tu'ipelehake of Tonga, former Centers for Disease Control Director, Dr. David J. Sencer (1966–1977), and former Assistant Surgeon General, Dr. J. Donald Millar. Several years prior to his visit to the CDC in 1967, Prince Tu'ipelehake met a CDC team that was headed by Dr. Ronald R. Roberto. This team provided the smallpox vaccine, which was delivered by a newly developed jet gun, to the local people of Tonga. During this subsequent visit to the CDC, he met with the smallpox and sanitation officials in order to learn more about the organization, in an attempt to implement a method of communications in case his country would ever need future CDC assistance.