Russian plague lab researcher's death raises concerns over pneumonic plague

Fox News senior medical analyst Dr. Marc Siegel discusses the death of a Russian researcher raising biosafety concerns on 'Fox News Sunday.'

Dr. Marc Siegel joins Shannon Bream to analyze the mysterious death of a researcher at a Russian plague laboratory, raising concerns about the pneumonic plague. Siegel discusses the lack of scientific transparency from Russia. He also highlights his upcoming book, 'The Angels Among Us.'