
The U.S. May Soon Have a Third Vaccine. Here's How It Works
As the Biden administration promises to accelerate the U.S. coronavirus vaccine rollout, it could soon have a new tool: A single-dose vaccine that can survive up to three months in an ordinary refrigerator. Manufacturer Johnson & Johnson released data today showing that its single-dose version provided strong protection against COVID-19. Yet the news came with two caveats: The candidate’s efficacy rate—72 percent in the United States—is lower than the 95 percent rates boasted by the two-dose versions from Pfizer-BioNTech and Moderna that are currently approved for use in the U.S.