摘要：The 1918 influenza pandemic spread rapidly around the globe, leading to high mortality and social disruption. The countermeasures available to mitigate the pandemic were limited and relied on nonpharmaceutical interventions. Over the past 100 years, improvements in medical care, influenza vaccines, antiviral medications, community mitigation efforts, diagnosis, and communications have improved pandemic response. A number of gaps remain, including vaccines that are more rapidly manufactured, antiviral drugs that are more effective and available, and better respiratory protective devices. The 1918 H1N1 influenza pandemic was unprecedented, with rapid global spread and high mortality. The potential for an influenza pandemic remains a constant public health threat. If a pandemic like the one in 1918 were to happen today, it would be likely to overwhelm the health care infrastructure and would require significant increases in the production, supply, and distribution of potentially life-saving pharmaceuticals and medical supplies. The devastating pandemic that emerged in 1918 caused at least 50 million deaths worldwide, 675 000 of which occurred in the United States. 1 At that time, there were very limited countermeasures to mitigate the global spread of or treat infections from the 1918 H1N1 virus. There were no diagnostic tests available to confirm infection, no influenza vaccine available to prevent infection, and no antiviral medications that could reduce severity and duration of symptoms. Critical care measures, such as intensive care support or mechanical ventilators, were not available. The 1918 pandemic predated antibiotics, leaving those infected with limited treatment options for secondary bacterial coinfections. Since 1918, the world has experienced three subsequent pandemics. The estimated global mortality associated with these events was significantly lower, with approximately 1 million for the 1957 H2N2 and 1968 H3N2 pandemics and fewer than 0.3 million for the first year of the 2009 H1N1 pandemic. 1 Despite the lower impact of recent pandemics, the potential for a pandemic with very high severity remains. Public health officials are watching one avian influenza A virus, A (H7N9) in China, very closely. Since 2013, it has caused a high number of human infections, 1567 so far, with a case–fatality proportion of around 40%. 2 While advances in medical care and countermeasures contributed to a reduction in deaths in the past three pandemics, and although these measures are widely available today, a novel influenza A virus could abruptly change to become a more human-adapted virus, spreading efficiently from person to person and causing significant morbidity and mortality worldwide. Given these current risks, the centenary of the 1918 H1N1 pandemic is an appropriate time to review the state of countermeasures then, highlight progress made over time to the current state, and identify remaining gaps to better prepare us for the next pandemic.
