PNAS: Gao Fu/Liu Jinhua and others report that the recent H1N1 swine flu virus is highly infectious to humans

Pigs are considered important hosts or 'hybrid containers' for the production of pandemic influenza virusesSystematic monitoring of the swine flu virus is essential for early warning and the prevention of the next potential pandemicRecently, Chinese researchers reported on the surveillance of the swine flu virus in China from 2011 to 2018 and identified a recently emerging genotype 4 (G4) recombination Eurasian poultry (EA) H1N1 virus, which has an internal gene derived from the 2009 pandemic (pdm/09) and triple recombination (TR), which has been dominant in the pig population since 2016similar to the pdm/09 virus, the G4 virus can bind to human receptors, and it produces much more progenitor viruses in human airway cortex cells, showing efficientinfectionand aerosol transmission in ferrets, the low cross-reactivity of the human influenza vaccine strain with the antigen of the G4 severe EA H1N1 virus indicates that the existing groupimmunedoes not protect the G4 virusfurther serological monitoring in occupational-exposed populations showed that 10.4% (35/338) of pig workers tested positive for G4 EA H1N1 virus, especially participants aged 18 to 35, with a seropositive rate of 20.5% (9/44), indicating that the G4 EA H1N1-based virus had gained greater human infectionthis infection greatly enhances the chances of the virus adapting in humans and raises concerns about the potential for pandemic viruses