Just when we thought coronavirus was somewhat behind us, a report in the proceedings of the National Academy of the Natural Sciences published on Monday described the discovery of an influenza virus discovered in China that has the potential to develop into a pandemic.
The surveillance of the pig population carried out from 2011 to 2018 in China is essential for early warning and preparedness for the next potential pandemics. From these samples, researchers identified 179 swine influenza viruses. When multiple strains of influenza viruses infect the same pig, they can easily swap genes, a process known as “reassortment.” The new study claims that the new virus, identified as EA H1N1 and dubbed G4, is a unique blend of three virus strains including an avian virus and the virus responsible for the 2009 Swine Flu pandemic.
Sun Honglei, the paper’s first author, says the inclusion of genes from the 2009 pandemic “may promote the virus adaptation” that leads to human-to-human transmission. Therefore, “It’s necessary to strengthen the surveillance” of Chinese pigs for influenza viruses, says Sun.
Influenza viruses frequently jump from pigs to humans, but most do not then transmit between humans. Evidence of initial infection has already been found in people who work in abattoirs and the swine industry and more than 10% of the workers were found to be infected. The tests also showed that as many as 4.4% of the general population also appeared to have been exposed.
The new strain is particularly concerning as humans have no immunity to avian viruses. If a human is infected, the virus can grow and multiply in the cells that line the human airways. Current flu vaccines do not appear to protect against it, although they could be adapted to do so if needed.
This newly discovered virus is a strain of the Swine Flu responsible for the pandemic in 2009 that infected 700 million to 1.4 billion people and caused about 284,000 deaths. A strain of the H1N1 influenza virus was responsible for the 1918–1920 Spanish flu pandemic that infected 500 million people–about a third of the world’s population at the time– and killed 17-50 million, and possibly as high as 100 million, making it one of the deadliest pandemics in human history.