Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, said he "seriously doubt[ed the Russians have come up with a vaccine for the coronavirus], Yahoo News reported.
In an interview with ABC, Fauci said Russia has approved the locally-developed vaccine and is on the fast-track to mass administering it to the general public.
According to new sources, the country's top diplomats have already received the treatment.
Fauci also said his family had been receiving death threats, questioning how this made sense with him working to create a cure for the disease.