Containment, deconfinement, spread, R0, Rt, vaccine, herd immunity, pulmonary embolism, hydroxychloroquine... We have all become familiar with this vocabulary amid the coronavirus crisis. However, we have never been so aware of the weakness of our knowledge in epidemiology. To better understand the situation, Yabiladi interviewed Moroccan epidemiologist and researcher at the University of Massachusetts in the United States Youssef Oulhoute.