The coronavirus would give way in the dark future to swine flu viruses … A study worries about a possible new global pandemic.
Bad news is taking hold in the minds of many scientists. According to a study published Monday, June 29, in the American scientific journal PNAS, researchers have discovered a strain of swine flu virus in China that has all the characteristics of a future pandemic.
As the France-Presse (AFP) agency explains to us, these viruses, called G4, genetically descend from the H1N1 strain, which is at the origin of a pandemic that occurred in 2009. And the authors, brilliant scientists from Chinese universities and the China Center for Disease Prevention and Control are alerting the world by stating that viruses "have all the essential traits that show high adaptability to infect humans."
A gigantic analysis
Between 2011 and 2018, 30,000 nasal swabs were taken from pigs in slaughterhouses in 10 Chinese provinces and in a veterinary hospital. Thanks to this, experts were able to isolate 179 swine flu viruses. For the majority of pigs, a new variety had infected them since 2016. In the laboratory, the researchers then carried out various experiments which led to an observation: the symptoms of pigs are the same as those of humans, they have a fever, cough and sneeze.
They also discovered that G4s were highly infectious, replicated in human cells, and caused more severe symptoms than other strains. And via in vitro tests, the immunity obtained after contact with human seasonal flu viruses would not protect against G4.
Workers and people who worked with pigs were relatively likely to have been infected, 10.4%, according to blood tests that looked for antibodies to the virus. 4.4% of the general population also appeared to be infected.
But, and the study specifies it very well, the virus passed in humans would not be transmitted from human to human, report the scientists,
Surveillance
"Pandemics occur when influenza A viruses with a new HA surface antigen become capable of being transmitted from human to human. The concern is that infections of humans with G4 viruses do not lead to human adaptation and do not increase the risk of a human pandemic, "say the researchers.
For the latter, increased surveillance is needed "of populations working in contact with pigs."
"The work is a salutary reminder that we constantly run the risk of the emergence of zoonotic pathogens, and that farm animals, with which humans are more in contact than with wild animals, are the source of pandemic viruses important, "James Wood, head of the department of veterinary medicine at the University of Cambridge, told AFP.