On April 24, 2009, for the first time in Mexican history, President Felipe Calderón invoked the emergency health powers outlined in Mexico's Constitution and General Health Law.1,2 The catalyst for this dramatic action was the appearance of a novel strain of influenza A(H1N1) of unclear severity. Harkening back to measures that originated in the late 14th century, when bubonic plague stalked much of Europe and Asia prompting ports and nation-states to order mass quarantines, Mexico instituted a broad-based and exacting menu of community mitigation strategies, or nonpharmaceutical interventions (NPIs), including school closure, public gathering bans, isolation, quarantine, and social distancing.