6 reasons why new swine flu virus in China is a serious worry
Even as the world is grappling with the COVID-19 pandemic, Researchers in China have discovered a new type of swine flu that is capable of triggering a pandemic. The new strain of influenza was recently discovered in pigs that has the potential to infect humans. Named G4, it is genetically descended from the H1N1 strain that caused a pandemic in 2009. The virus can grow and multiply in the cells that line the human airways. They found evidence of recent infection starting in people who worked in abattoirs and the swine industry in China.Current flu vaccines do not appear to protect against it, although they could be adapted to do so if needed.
Here are 6 reasons why new swine flu virus is a serious worry
The G4 EA H1N1 flu virus is already circulating among swine
It has been getting around and reproducing among the swine population in China for a while. Between 2011 and 2018, researchers took 30,000 nasal swabs from pigs in slaughterhouses in 10 Chinese provinces. From 2011 to 2013 the most common variant of the EA H1N1 flu virus was the genotype 1 (G1) strain. But mutations in this strain eventually led to the emergence of a genotype 4 (G4) variant. Every year since 2014, this G4 variant became more and more common eventually, surpassing its original G1 master to become the single predominant genotype of the EA H1N1 flu virus among the swine population in China.
The G4 EA H1N1 flu virus can bind to human-like SAα2,6Gal receptors
“SAα2,6Gal” is the name of a receptor found on cells that line your respiratory tract. Binding such receptors could help the virus attach itself to and eventually get into your cells.
The virus can attach itself to human cells
It is not just any random human cell but cells that line with trachea. Trachea is the windpipe, the tube that connects upper respiratory tract with the lower part of our respiratory tract and lungs. So if a virus can bind to the cells that constitute your trachea, it could subsequently make its way down into your lungs.
Ferrets infected with the virus can spread the virus to other ferrets via respiratory droplets or direct contact
The researchers carried out various experiments including on ferrets, which are widely used in flu studies because they experience similar symptoms to humans -- principally fever, coughing and sneezing. G4 was observed to be highly infectious, replicating in human cells and causing more serious symptoms in ferrets than other viruses.
The virus is different from the virus strains that are already in flu vaccines
G4 EA H1N1 flu virus can infect and reproduce in cells lining your lower respiratory tract. Tests also showed that any immunity humans gain from exposure to seasonal flu does not provide protection from G4.
The virus has already infected humans and seems to be more infectious
More than one in 10 swine workers in the new study had already been infected, according to antibody blood tests which showed exposure to the virus. The tests also showed that as many as 4.4% of the general population also appeared to have been exposed.The virus has therefore already passed from animals to humans but there is no evidence yet that it can be passed from human to human – the scientists’ main worry.
