This archive report was first published on 30 June 2020.
June 30, 2020, marked a significant day in the world of virology as researchers in China announced the discovery of a new type of swine flu, named G4, which has the potential to trigger a pandemic.
According to a study published in the US science journal PNAS, G4 is genetically descended from the H1N1 strain that caused a pandemic in 2009.
The researchers, who are scientists at Chinese universities and China's Center for Disease Control and Prevention, isolated 179 swine flu viruses from 30,000 nasal swabs taken from pigs in slaughterhouses in 10 Chinese provinces and a veterinary hospital between 2011 and 2018.
The majority of the viruses were of a new kind, which has been dominant among pigs since 2016.
Experiments conducted on ferrets, which are widely used in flu studies, showed that G4 was highly infectious and caused more serious symptoms than other viruses.
Tests also revealed that any immunity humans gain from exposure to seasonal flu does not provide protection from G4.
Alarmingly, blood tests showed that 10.4 percent of swine workers had already been infected, and as many as 4.4 percent of the general population appeared to have been exposed.
While there is no evidence yet that G4 can be passed from human to human, the scientists' main worry is that human infection of the virus will further human adaptation and increase the risk of a human pandemic.
Chinese foreign ministry spokesman Zhao Lijian stated that China has been paying close attention to the development of the virus and will take all needed action to prevent its spread and any outbreaks.
The study's authors called for urgent measures to monitor people working with pigs, and experts warn that the discovery serves as a reminder of the constant risk of new emergence of zoonotic pathogens.
