Influenza’s Plummeting During the COVID-19 Pandemic: The Roles of Mask-Wearing, Mobility Change, and SARS-CoV-2 Interference
Shasha Han,
Ting Zhang,
Yan Lyu,
Shengjie Lai,
Peixi Dai,
Jiandong Zheng,
Weizhong Yang,
Xiao-Hua Zhou,
Luzhao Feng
Affiliations
Shasha Han
Beijing International Center for Mathematical Research, Peking University, Beijing 100871, China; Harvard Medical School, Harvard University, Boston, MA 02115, USA
Ting Zhang
School of Population Medicine and Public Health, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100730, China
Yan Lyu
Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China
Shengjie Lai
WorldPop, School of Geography and Environmental Science, University of Southampton, Southampton SO17 1BJ, UK
Peixi Dai
Division for Infectious Diseases, Chinese Center for Disease Control and Prevention, Beijing 102206, China
Jiandong Zheng
Department of Epidemiology and Biostatistics, School of Public Health, Peking University, Beijing 100871, China
Weizhong Yang
School of Population Medicine and Public Health, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100730, China
Xiao-Hua Zhou
Beijing International Center for Mathematical Research, Peking University, Beijing 100871, China; Department of Epidemiology and Biostatistics, School of Public Health, Peking University, Beijing 100871, China; National Engineering Laboratory of Big Data Analysis and Applied Technology, Peking University, Beijing 100871, China; Corresponding authors.
Luzhao Feng
School of Population Medicine and Public Health, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100730, China; Corresponding authors.
Seasonal influenza activity typically peaks in the winter months but plummeted globally during the current coronavirus disease 2019 (COVID-19) pandemic. Unraveling lessons from influenza’s unprecedented low profile is critical in informing preparedness for incoming influenza seasons. Here, we explored a country-specific inference model to estimate the effects of mask-wearing, mobility changes (international and domestic), and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) interference in China, England, and the United States. We found that a one-week increase in mask-wearing intervention had a percent reduction of 11.3%–35.2% in influenza activity in these areas. The one-week mobility mitigation had smaller effects for the international (1.7%–6.5%) and the domestic community (1.6%–2.8%). In 2020–2021, the mask-wearing intervention alone could decline percent positivity by 13.3–19.8. The mobility change alone could reduce percent positivity by 5.2–14.0, of which 79.8%–98.2% were attributed to the deflected international travel. Only in 2019–2020, SARS-CoV-2 interference had statistically significant effects. There was a reduction in percent positivity of 7.6 (2.4–14.4) and 10.2 (7.2–13.6) in northern China and England, respectively. Our results have implications for understanding how influenza evolves under non-pharmaceutical interventions and other respiratory diseases and will inform health policy and the design of tailored public health measures.
