[ ]these pandemics also have several similarities, including the populations at risk medically (e g , people with lung and heart diseases) and those who are vulnerable socially (e g , poor, immigrant, and Indigenous people) 2,3 The role of nonpharmaceutical interventions, such as handwashing, social distancing, and travel restrictions, in infection mitigation is another lesson from historic pandemics that appears translatable to COVID-19 45 The earliest studies on the waves of the 1918 influenza pandemic have considered, for example, the number, severity, height, and length of waves, as well as possible cross-protection between them Future studies could analyze the wavelike behavior of the 1918 influenza pandemic among subgroups with particular medical (e g , age, comorbidities) and social (e g , gender, socioeconomic status, race/ethnicity) variables Socioeconomic risk groups, vaccination and pandemic influenza, funded by the Research Council of Norway 2020-2023 (grant 302336) and (2) CorRisk: Early COVID-19 wave in Norway: social inequality in morbidity, compliance to nonpharmaceutical interventions and labour marked consequences, funded by the Research Council of Norway 2020-2021 (grant 312716)
COVID-19: The Power of Historical Lessons