Covid Shots Barrel Toward Finish Line in 300-Day Science Feat

In early January, about the only thing the world’s scientists knew for sure about the novel coronavirus was its genetic profile. Now, some 300 days later, vaccine developers are on the brink of a major victory against a pathogen that’s inflicted untold personal and economic damage.

Virus specialists including Anthony Fauci, the top U.S. infectious disease doctor, predicted in early 2020 that it would take a year to 18 months to develop a vaccine to confront the contagion. Moderna Inc. and Pfizer Inc.’s collaboration with BioNTech SE are poised to beat that forecast if preliminary positive results from their ...