KTSA: COVID-19 questions answered Posted on April 8, 2020 at 8:28 am.Shared by contributor Dr. Anthony Hartzler, Infectious Diseases/General & Hospital Medicine, was a guest on KTSA radio’s Jack Riccardi Show speaking on COVID-19, the development of a vaccine and the use of cloth face masks by the general public. Listen below: KTSAAM-3453 Share This Article!