Claim: Despite cold War tensions Mikhail Chumakov, a Soviet microbiologist and virologist, traveled to the U.S. to study the Salk polio vaccine.
Evidence: Mikhail Petrovich Chumakov (Russian: Миха′ил Петр′ович Чумак′ов) (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.