Zhang Jianhua, owner of a hog farm in Qiongjie county, Shannan, Tibet autonomous region, vaccinates a piglet on April 21, 2020. Photo:Xinhua

The pig influenza virus bearing the genotype 4 (G4) does not constitute an immediate threat of a pandemic outbreak, according to the latest research by the Chinese Center for Disease Control and Prevention (CDC).

The risk of pandemic influenza caused by the G4 genotype virus has not increased, the CDC said in the research and analysis published on its website on Friday.

The Eurasian avian-like H1N1 (EA-H1N1) swine influenza viruses including the G4 genotype virus can infect humans, but they do not yet have the ability to pass from person to person, said the CDC.

The probability of the general public being infected is extremely low, the CDC said, while suggesting that attention should be paid to maintaining good personal and environmental hygiene in daily life and minimizing contact with livestock, poultry and wild animals. 

It was found that the G4 genotype virus can bind to the human influenza virus receptor of the human upper respiratory tract and can be transmitted through the droplets between ferrets via in vitro experiments and animal experiments.

The CDC research followed a paper published on Monday by Chinese scientists on prevalent EA-H1N1 swine influenza viruses with 2009 pandemic viral genes facilitating human infection.

The study detected a pig influenza virus bearing G4, which is contagious among pigs and has the possibility of jumping to humans, as the G4 virus is able to bind with human cells. 

Based on the collection of samples between 2011 and 2018 among pigs in 10 Chinese provinces and regions, the study found that the virus was prevalent in pigs since 2016. Some 10.4 percent (35/338) of pig farm workers tested positive for antibodies against the virus, according to the paper.

The findings soon triggered public concerns over another pandemic like COVID-19 and whether the virus would exert an impact on the hog industry, which has only recently seen signs of recovery after African swine fever (ASF), which was prevalent in 2018-19.

Global Times