Alexandre Yersin

Alexandre Yersin (1863-1943) was a Swiss-born physician and bacteriologist who obtained French citizenship in 1888 and is remembered as a pioneer of microbiology and immunology. Working with Emile Roux in Paris in 1890, he helped co-discover the toxins responsible for diphtheria and tetanus. In 1894 in Hong Kong he isolated the bacterium responsible for bubonic plague, later named Yersinia pestis in his honor, and demonstrated that the same organism infected both rodents and humans, work that clarified how the disease spread. Yersin spent most of his later career in French Indochina, founding a Pasteur Institute branch in Nha Trang, Vietnam, and introducing rubber cultivation and quinine-producing cinchona trees to the region; he never returned to Europe, and after Vietnamese independence streets, schools and a university were named in his honor.