The Delta variant of the coronavirus is the cause of more than 80% of new U.S. COVID-19 cases, but the authorized vaccines remain more than 90% effective in preventing hospitalizations and deaths, said top U.S. infectious disease expert Anthony Fauci during U.S. Senate hearing on Tuesday. #COVID #Delta #Fauci #RandPaul #COVID19 #News #Reuters 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: https://www.facebook.com/Reuters Follow Reuters on Twitter: https://twitter.com/Reuters Follow Reuters on Instagram: https://www.instagram.com/reuters/?hl=en