1818, 1918, 2018: Two Centuries of Pandemics.

2018 marks the centennial of the 1918 influenza pandemic, widely acknowledged as one of the deadliest infectious disease crises in human history. As public health and medical communities of practice reflect on the aftermath of the influenza pandemic and the ways in which it has altered the trajectory of history and informed current practices in health security, it is worth noting that the Spanish flu was preceded by a very different 100-year threat: the first Asiatic cholera pandemic of 1817 to 1824. In this commentary, we offer a historical analysis of the common socioeconomic, political, and environmental factors underlying both pandemics, consider the roles of cholera and Spanish flu in shaping global health norms and modern public health practices, and examine how strategic applications of soft power and broadening the focus of health security to include sustainable development could help the world prepare for pandemics of the future.