摘要
Dear Editor,Since it first appeared in humans in China in 2013,a novel H7N9influenza virus has caused 1,568 cases of infection,with a mortality rate of 39.2%(Yin et al.,2021).The early H7N9 virus strains had low pathogenicity and did not cause avian disease(Zhang et al.,2013).However,they caused concern about poultry consumption and caused huge economic losses to the poultry industry.Since mid-2016,some H7N9 viruses mutated.
基金
the National Key Research and Development Program(2021YFD1800201)
Shandong Provincial Key Research and Development Program(2022CXGC010606)
Natural Science Foundation of Ningxia Hui Autonomous Region(2022AAC02071)。
