WHO Collaborating Centre for Reference and Research on Influenza,Royal Melbourne Hospital at the Peter Doherty Institute for Infection and Immunity,Victoria,3000,Australia; andSchool of Public Health and Preventive Medicine,Monash University,553 St Kilda Road,Melbourne,Australia.
WHO Collaborating Centre for Reference and Research on Influenza,Royal Melbourne Hospital and the Doherty Department,University of Melbourne at the Peter Doherty Institute for Infection and Immunity,Victoria,3000,Australia; andMelbourne School of Population and Global Health,The University of Melbourne,Melbourne,3000,Australia.
Epidemiol Infect. 2019 Jan;147:e213. doi: 10.1017/S095026881900102X.
The epidemiology of H5N1 and H7N9 avian viruses of humans infected in China differs despite both viruses being avian reassortants that have inherited six internal genes from a common ancestor, H9N2. The median age of infected populations is substantially younger for H5N1 virus (26 years) compared with H7N9 virus (63 years). Population susceptibility to infection with seasonal influenza is understood to be influenced by cross-reactive CD8+ T cells directed towards immunogenic peptides derived from internal viral proteins which may provide some level of protection against further influenza infection. Prior exposure to seasonal influenza peptides may influence the age-related infection patterns observed for H5N1 and H7N9 viruses. A comparison of relatedness of immunogenic peptides between historical human strains and the two avian emerged viruses was undertaken for a possible explanation in the differences in age incidence observed. There appeared to be some relationship between past exposure to related peptides and the lower number of H5N1 virus cases in older populations, however the relationship between prior exposure and older populations among H7N9 virus patients was less clear.
在中国感染的 H5N1 和 H7N9 禽流感病毒的流行病学不同，尽管这两种病毒都是禽源重配病毒，它们从共同祖先 H9N2 那里继承了六个内部基因。感染人群的中位年龄，H5N1 病毒（26 岁）显著低于 H7N9 病毒（63 岁）。人们对季节性流感的易感性被认为受到针对来自内部病毒蛋白的免疫原性肽的交叉反应性 CD8+ T 细胞的影响，这些 T 细胞可能对进一步的流感感染提供一定程度的保护。季节性流感肽的先前暴露可能会影响观察到的 H5N1 和 H7N9 病毒的年龄相关感染模式。为了说明观察到的年龄发病率差异，对历史人类株和两种新出现的禽流感病毒之间免疫原性肽的相关性进行了比较。过去接触相关肽与老年人群中 H5N1 病毒病例数量较少之间似乎存在一定关系，然而，在 H7N9 病毒患者中，先前暴露与老年人群之间的关系不太明确。
