In what Pfizer CEO Albert Bourla calls “likely the most significant medical advancement in the last 100 years,” BioNtech and Pfizer’s Covid-19 vaccine may prove to be more than 90% effective in preventing coronavirus. CNBC’s Senior Health and Science Reporter Meg Tirrell breaks the good news with the Squawk Box anchors, and Pfizer CEO Dr. Albert Bourla discusses the success, the implications, and the questions still unanswered. In an extended interview, Bourla thanks his scientists for their ongoing work to change the course of history and outlines the road ahead.