Drug companies around the world are working to develop a vaccine for Covid-19.
Drug companies around the world are working to develop a vaccine for Covid-19. Drug companies around the world are working to develop a vaccine for Covid-19. In mid-November, both Pfizer and BioNTech and Moderna, report that — based on early data — they have vaccines that are about 90 percent and 94 percent effective against Covid-19, respectively. Even with this news, Vox’s Umair Irfan reports, many key steps remain before a vaccine is rolled out.