Prevalent Eurasian avian-like H1N1 swine influenza virus with 2009 pandemic viral genes facilitating human infection

Abstract

Pigs are considered as important hosts or “mixing vessels” for the generation of pandemic influenza viruses. Systematic surveillance of influenza viruses in pigs is essential for early warning and preparedness for the next potential pandemic. Here, we report on an influenza virus surveillance of pigs from 2011 to 2018 in China, and identify a recently emerged genotype 4 (G4) reassortant Eurasian avian-like (EA) H1N1 virus, which bears 2009 pandemic (pdm/09) and triple-reassortant (TR)-derived internal genes and has been predominant in swine populations since 2016. Similar to pdm/09 virus, G4 viruses bind to human-type receptors, produce much higher progeny virus in human airway epithelial cells, and show efficient infectivity and aerosol transmission in ferrets. Moreover, low antigenic cross-reactivity of human influenza vaccine strains with G4 reassortant EA H1N1 virus indicates that preexisting population immunity does not provide protection against G4 viruses. Further serological surveillance among occupational exposure population showed that 10.4% (35/338) of swine workers were positive for G4 EA H1N1 virus, especially for participants 18 y to 35 y old, who had 20.5% (9/44) seropositive rates, indicating that the predominant G4 EA H1N1 virus has acquired increased human infectivity. Such infectivity greatly enhances the opportunity for virus adaptation in humans and raises concerns for the possible generation of pandemic viruses.

SARS-CoV-2 infects cells following viral entry via clathrin-mediated endocytosis

“…All originated in bats but zoonotic transmission involved intermediate hosts; dromedary camels (MERS-CoV), civets (SARS-CoV), and unknown (SARS-CoV-2). The presence of numerous coronaviruses in bats suggests that zoonotic transmission to humans will continue (Tortorici and Veesler, 2019), and new pandemic potential viruses continue to emerge (Sun et al, 2020).…”

Microbicidal actives with virucidal efficacy against SARS-CoV-2 and other beta- and alpha-coronaviruses: implications for future emerging coronaviruses and other enveloped viruses

“…The virucidal e cacies would be expected 22 to apply also to other emerging enveloped viruses, such as Ebola virus 62,63 , Lassa virus, Nipah virus, and in uenza viruses such as the recently emerging G4 genotype H1N1 swine in uenza virus 64 and the variant in uenza viruses (H1N1v, H3N2v, H1N2v) in humans 65 . The latter expectation is supported by our own unpublished data on in uenza strains and by a recent literature review 59 .…”

“…Each of these formulated microbicidal actives resulted in complete inactivation (≥3 to ≥6 log 10 reduction in infectious titer) of the challenge coronaviruses, including SARS-CoV-2. These surface-and personal-care hygiene agents should, therefore, be useful in IPAC for SARS-CoV-2, future emerging coronaviruses, and other emerging enveloped viruses 22 (such as Ebola virus, Lassa virus, Nipah virus, and new strains of in uenza virus such as the recently emerging G4 genotype H1N1 swine in uenza virus 64 and the variant in uenza viruses (H1N1v, H3N2v, H1N2v) in humans 65 ).…”

Sunlight and Protection Against Influenza

“…Our result is potentially relevant not just to the current COVID-19 pandemic, but also to a future outlier H1N1 pandemic. The threat is there; some H1N1 viruses already exist in animals (Sun et al 2020). One must be cautious, though, with generalizations, given the unique economic circumstances (e.g., a 25-year high unemployment rate) in the fall of 2009.…”