The rapid global evolution of influenza virus begins with mutations that arise de novo in individual infections, but little is known about how evolution occurs within hosts. We review recent progress in understanding how and why influenza viruses evolve within human hosts. Advances in deep sequencing make it possible to measure within-host genetic diversity in both acute and chronic influenza infections. Factors like antigenic selection, antiviral treatment, tissue specificity, spatial structure, and multiplicity of infection may affect how influenza viruses evolve within human hosts. Studies of within-host evolution can contribute to our understanding of the evolutionary and epidemiological factors that shape influenza virus’s global evolution.

流感病毒的快速全球进化始于在个体感染中从头出现的突变，但人们对宿主内部进化的方式知之甚少。我们回顾了在了解流感病毒如何以及为什么在人宿主中进化的最新进展。深度测序技术的进步使测量急性和慢性流感感染的宿主内部遗传多样性成为可能。诸如抗原选择，抗病毒治疗，组织特异性，空间结构和感染多样性等因素可能会影响流感病毒在人宿主中的进化方式。宿主内部进化的研究可以帮助我们理解影响流感病毒全球进化的进化和流行病学因素。