Dr. Mocef Slaoui, chief science advisor for Operation Warp Speed, explains the administration’s decision and the impact it could have on vaccine doses for Americans. LEARN MORE: At 'vaccine summit,' Trump set to issue order that Americans get 1st access: https://abcn.ws/3n1sPvs Subscribe to GMA's YouTube page: https://bit.ly/2Zq0dU5 Visit GMA's homepage: https://www.goodmorningamerica.com Follow GMA: TikTok: tiktok.com/@gma Facebook:facebook.com/GoodMorningAmerica Twitter: twitter.com/gma Instagram: instagram.com/goodmorningamerica #GMA #Pfizer #COVID19Vaccine #WhiteHouse #OperationWarpSpeed