Top U.S. infectious disease expert Dr. Anthony Fauci explained why classical herd immunity is improbable, saying 'protection that follows infection is not particularly durable' with COVID. #News #Reuters #UnitedStates #COVID #AnthonyFauci Subscribe: http://smarturl.it/reuterssubscribe Reuters brings you the latest business, finance and breaking news video from around the globe. Our reputation for accuracy and impartiality is unparalleled. Get the latest news on: http://reuters.com/ Follow Reuters on Facebook: / reuters Follow Reuters on Twitter: / reuters Follow Reuters on Instagram: https://www.instagram.com/reuters/?hl=en