Stamp France Yvert et Tellier No. 4798/99 mint never hinged. 150th anniversary of the birth of the Franco-Swiss doctor and bacteriologist Alexandre Yersin, who is credited with discovering the plague bacillus. It should be noted that these stamps are part of a joint issue with Vietnam, as Alexandre Yersin passed away on February 28, 1943, in Nha Trang (French Indochina).
