School of Public Health, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong, China.
HKU-Pasteur Research Pole, School of Public Health, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong, China.
Nat Commun. 2022 Mar 31;13(1):1721. doi: 10.1038/s41467-022-29402-5.
Annual epidemics of seasonal influenza cause hundreds of thousands of deaths, high levels of morbidity, and substantial economic loss. Yet, global influenza circulation has been heavily suppressed by public health measures and travel restrictions since the onset of the COVID-19 pandemic. Notably, the influenza B/Yamagata lineage has not been conclusively detected since April 2020, and A(H3N2), A(H1N1), and B/Victoria viruses have since circulated with considerably less genetic diversity. Travel restrictions have largely confined regional outbreaks of A(H3N2) to South and Southeast Asia, B/Victoria to China, and A(H1N1) to West Africa. Seasonal influenza transmission lineages continue to perish globally, except in these select hotspots, which will likely seed future epidemics. Waning population immunity and sporadic case detection will further challenge influenza vaccine strain selection and epidemic control. We offer a perspective on the potential short- and long-term evolutionary dynamics of seasonal influenza and discuss potential consequences and mitigation strategies as global travel gradually returns to pre-pandemic levels.
季节性流感每年都会引发数十万人死亡、大量发病和巨大的经济损失。然而，自 COVID-19 大流行开始以来，公共卫生措施和旅行限制极大地抑制了全球流感传播。值得注意的是，自 2020 年 4 月以来，乙型/Yamagata 系流感一直未被明确检测到，而 A(H3N2)、A(H1N1)和 B/Victoria 病毒的传播遗传多样性明显减少。旅行限制将 A(H3N2)的区域性暴发主要限制在南亚和东南亚、B/Victoria 在中国、A(H1N1)在西非。除了这些特定的热点地区，季节性流感传播谱系继续在全球范围内消失，这些热点地区很可能引发未来的疫情。人群免疫力下降和偶发病例的检测将进一步挑战流感疫苗株的选择和疫情控制。我们提供了对季节性流感潜在短期和长期进化动态的看法，并讨论了随着全球旅行逐渐恢复到大流行前水平，可能出现的后果和缓解策略。
