In the world of contagions, epidemics and vaccines, there are not many true rock stars. There is, of course, Dr. Anthony Fauci, who directs the National Institute of Allergy and Infectious Diseases. His face is recognizable worldwide from his television briefings on the coronavirus epidemic sweeping the globe. Another is Dr. Michael Osterholm, director of the Center for Infectious Disease Research and Policy at the University of Minnesota. His assistance is routinely sought by world leaders when a new pathogen threatens.