requirement because the airline is a government contractor. american did not say when this will take effect and did say that testing will not be an alternative. meanwhile the drug company merck announced its experiment aal , ridgeback biotherapeutics plan to get approval as soon as possible. author of "spread" how we can defeat the next pandemic. dr. gottlieb, thanks for joining us. this antiviral pill from merck. how significant is this? >> very significant. this is the most impactful result that i remember seeing in the oral drug in the treatment of a respiratory pathogen perhaps ever. i think getting an oral pill that can inhibit viral replication that can inhibit this virus will be a real game