What Happens to the Other Vaccines Now?

(Bloomberg Opinion) -- A vaccine created by Pfizer and partner BioNTech won the race to prove efficacy in a large trial. But is it the best vaccine of the dozens being tested? If it isn’t, will any slower but better vaccines have a chance?A press release this week claims the vaccine is 90% effective at preventing symptomatic Covid-19. That would mean nearly all of those infections happened in people who got a placebo rather than the vaccine.The trial isn’t over. It was slated to stop after...