Mikhail Chumakov Mikhail Chumakov Mikhail Petrovich Chumakov () (November 14, 1909 – June 11, 1993) was a Soviet microbiologist and virologist most famous for conducting pivotal large-scale clinical trials that led to licensing of the Oral Polio Vaccine (OPV) developed by Albert B. Sabin. Chumakov graduated in 1931 from Moscow State University Medical School that was later transformed into I.M. Sechenov Moscow Medical Academy. In 1937 Chumakov participated in a scientific expedition to Khabarovsk region of Soviet Far East that was led by Professor . Together with his colleagues he discovered the etiology of a new transmissible neurological disease called tick-borne encephalitis
Smallpox vaccine sheep were used. In the late 1940s and early 1950s, Leslie Collier, an English microbiologist working at the Lister Institute of Preventive Medicine, developed a method for producing a heat-stable freeze-dried vaccine in powdered form. Collier added 0.5% phenol to the vaccine to reduce the number of bacterial contaminants but the key stage was to add 5% peptone to the liquid vaccine before it was dispensed into ampoules. This protected the virus during the freeze drying process. After drying the ampoules were sealed under nitrogen. Like other vaccines, once reconstituted it became ineffective after 1–2 days at ambient temperatures. However,