Soviet bioweapons foulup leads to global epidemic

[Melvin Loh]

IIRC there was an accident at the USSR's bioweapons manufacturing plant in Semipalatinsk in the Ukraine in 1979, involving the accidental release of anthrax agents which killed some of the workers at the site. Now, WI that biweapons foulup or another like it hadn't been contained and somehow spread into a global epidemic ? How would the Cold War and the world generally have been affected by such a plague ?