Gao Fu and others found a new type of recombined swine flu virus: with epidemic potential

are considered important hosts or "hybrid containers" for pandemic influenza virus generation. Systematic surveillance of swine flu viruses is critical to early warning and preparation for the next potential pandemic. A team of researchers from China monitored the nasal swabs of nearly 30,000 pigs from 2011 to 2018 and found that a recombined influenza virus, G4 EA H1N1, had dominated the domestic swine flu virus since 2016 and had the potential to spread in the population. The team recommends rapid control of the G4 EA H1N1 virus in pigs and close monitoring of farmers.
above, prevalent Eurasian avian-like H1N1 swine influenza virus with 2009 pandemic virus genesing human human contact from the latest paper in the international authoritative journal
PNAS on June 29, local time. The paper was co-authored by Professor Liu Jinhua of the School of Animal Medicine of China Agricultural University and Gao Fu, Director of Cdcs, and first by Sun Honglei, Associate Researcher, Department of Preventive Veterinary Medicine, School of Animal Medicine, Agricultural University of China.
monitoring spanned 10 provinces and municipalities over an eight-year period. Specifically, the researchers collected 29918 pig nose swabs from pig farms in Anhui, Beijing, Hebei, Heilongjiang, Henan, Jiangsu, Jilin, Liaoning, Shandong and Tianjin, as well as 1,016 pig nose swabs or lung samples with respiratory symptoms. The researchers identified the H1N1 virus (G4 EA) of the recently recombined genotype 4 (G4) avian influenza (EA), which has internal genes derived from the 2009 H1N1 pandemic and triple recombination (TR) and has dominated pigs since 2016. Recombination means that when multiple influenza viruses infect the same pig, they easily exchange genes, a process known as "recombination".
Similar to the 2009 swine flu virus, the G4 virus binds to human-type lithums, produces more subgenerational viruses in human channel endocial cells, and exhibits efficient infectious and aerosol transmission capabilities in ferrets, a popular animal model for studying human influenza.
addition, the low antigen cross-reaction of the human influenza vaccine strain with the G4 recombinant EA H1N1 virus indicates that existing population immunity does not provide protection against the G4 virus. Further serological monitoring of occupational contact populations showed that 10.4% (35/338) of pig workers tested positive for the G4 EA H1N1 virus, especially those aged 18 to 35, with a serum-positive rate of 20.5% (9/44), indicating an increase in human infectiousness, mainly G4 EA H1N1 virus. This infectiousness greatly increases the chances of the virus adapting in humans and raises concerns about the possibility of a pandemic virus.
according to evolutionary tree analysis, EA H1N1 virus has G1-G6 six genotypes. G1 was the original EA H1N1, and other genotypes, including G4, were created between 2011 and 2018 when certain genes were replaced or mutated.
swab analysis showed that the G4 virus had emerged in 2013, became mainstream in 2016 and had an absolute majority in 2018.
The current data suggest that this appears to be an upcoming swine flu virus in humans," Edward Holmes, an evolutionary biologist at the University of Sydney who studies pathogens, was quoted as saying on the website Science. But the study also has its limitations: the sample is not big enough, with 500 million pigs in China. The study only gives a small understanding of the swine flu strain.
a household survey, researchers found that 4.4 percent of the 230 respondents had antibodies to G4, more than doubling the proportion among pig farmers, according to the paper. In addition to enhanced surveillance, Sun said it makes sense to develop a G4 vaccine for pigs and people.