No matter how well-prepared we are, there won’t immediately be enough coronavirus vaccine to immunize all Americans. Choices will have to be made about who goes to the front of the line. “It’s inevitable that the vaccine will come out more slowly than we like. We’re not going to have 350 million doses delivered day one,” said Andrew Pavia, chief of pediatric infectious diseases at the University of Utah in Salt Lake City. To be most protective, a list of the first to be immunized must be carefully crafted based on what type of vaccine may become available, who it works best for and whether the disease is still raging. Since 1964, the United States has relied on the Centers for Disease Control and Prevention’s Advisory Committee on Immunization Practices to make those decisions. As soon as the Food and Drug Administration licenses a new vaccine, ACIP offers guidelines on how it should be distributed, to whom and when. The World Health Organization has a similar group, the Strategic Advisory Group of Experts on Immunization. ACIP already has begun working on a plan for SARS-CoV-2, the virus that causes COVID-19. The WHO group began its process last week. “We’re starting as early as we can to deal with the torrent of data that’s coming out,” said Dr. Grace Lee, a professor of pediatrics at Stanford University School of Medicine and current ACIP member. “We don’t want to wait until the vaccine becomes available and begin our deliberations then.” Typically, ACIP’s guidelines would be used without question.