A Vaccine Breakthrough

It’s a dark time in the struggle with the coronavirus, particularly in the United States, where infections and hospitalizations have surged. But amid the gloom comes some light: A trial by the drug maker Pfizer has returned preliminary results suggesting that its vaccine is 90 percent effective in preventing Covid-19. With the virus raging, how strong is this new ray of hope? Guest: Carl Zimmer, a science writer and author of the “Matter” column for The New York Times. Background reading: Pfizer has announced positive early results from its coronavirus vaccine trial, cementing the lead in a frenzied global race that has unfolded at record-breaking speed.Meet the couple behind the German company, BioNTech, that partnered with Pfizer to develop the vaccine. We want to hear from you. Fill out our survey about this show and others at nytimes.com/thedailysurvey.