KGO ABC World News Tonight With David Muir December 4, 2020 01:40:00
>> we need to be very transparent with patients. >> reporter: dr. victoria smith participated in the pfizer trial in louisiana. >> one of the reasons why i wanted to participate was to be a model of participation and have my own example be a model of the safety of the vaccine and the process. >> reporter: and tonight, convincing people is a priority, but delivering a vaccine will be a challenge like never before. >> this is the biggest logistical challenge that the industry in general has ever faced. >> reporter: abc news getting an inside look at united's cold storage facility at chicago's o'...