Health experts say having a vaccine is just one front in a two-front battle against COVID-19. The other is effective treatments for those who are already sick with the disease. WSJ breaks down the three most promising types in development. Photo Illustration: Jacob Reynolds/WSJ. More from the Wall Street Journal: Visit WSJ.com: http://www.wsj.com Visit the WSJ Video Center: https://wsj.com/video On Facebook: / videos On Twitter: / wsj On Snapchat: https://on.wsj.com/2ratjSM #WSJ #Coronavirus #Covid19