An article by employees of Chinese universities and the Chinese Center for Disease Control and Prevention, published in the American scientific journal PNAS, reports on a new strain called G4, which is genetically derived from the H1N1 strain that caused the pandemic in 2009. The new strain has all the signs that it is well adapted to infect people.
In 2011-2018, researchers took 30,000 swine nasal swabs from slaughterhouses in 10 Chinese provinces and a veterinary hospital, which allowed them to isolate 179 swine flu viruses, most of which were the new species that has dominated pigs since 2016. conducted experiments - including on ferrets, which are known for experiencing symptoms similar to humans.
It turned out that G4 is very contagious, causes more serious symptoms in ferrets than other viruses, and can multiply in human cells. Immunity acquired by humans after seasonal flu does not provide protection against G4.
More than one in 10 pig workers has already been infected with the new strain, according to blood tests for antibodies. Tests also showed that up to 4.4% of the population as a whole also seemed to be exposed to it. Thus, the virus has already passed from animals to people.
However, so far there is no evidence that it can be transmitted from person to person. Nevertheless, the researchers write: "It is of concern that infection of a person with the G4 virus will contribute to further adaptation of the person and increase the risk of a pandemic".