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New Chinese Swine Flu Virus Has “Pandemic Potential”

Updated: Oct 18, 2021

According to a study published on June 29 in the Proceedings of the National Academy of Sciences Journal, several Chinese researchers have discovered a new strain of swine flu that has the potential to grow into a pandemic, but currently does not pose a global threat. The swine flu (also called the G4 virus), is genetically descended from the H1N1 swine flu strain that caused the 2009 pandemic. The new swine flu is currently only transmittable from pig to pig. However it is difficult to predict whether this strain will eventually mutate to readily transmit between humans.

“Pigs are considered important hosts for the generation of pandemic influenza viruses, and if this virus becomes more prominent, it certainly may have pandemic potential,” the researchers said in the study. In 2009, the H1N1 swine flu pandemic killed an estimated 151,700 – 575,400 people globally. In the aftermath, authorities and scientists stepped up surveillance of pig populations to watch for viruses that they deemed had the potential to grow into a pandemic.

When multiple strains of influenza viruses infect the same pig, they can easily swap genes, a process known as reassortment. This occurred in the G4 influenza virus and created a blend of three lineages. One is similar to strains found in European and Asian birds, another is the H1N1 strain that caused the 2009 pandemic, and lastly a North American H1N1 that has genes from avian, human, and pig influenza viruses.

G4 already appears to have infected humans in China, which has the largest pig population in the world. In Hebei and Shandong provinces, both places with high pig populations, more than 10% of swine workers on pig farms and 4.4% of the general population tested positive in a survey from 2016 to 2018.

As part of a project to identify potential pandemic influenza strains, a team led by Liu Jinhua from the China Agricultural University analyzed nearly 30,000 nasal swabs taken from pigs at slaughterhouses in 10 Chinese provinces and another 1,000 swabs from pigs with respiratory symptoms seen at their school’s veterinary teaching hospital. The swabs, collected between 2011 and 2018, resulted in 179 swine influenza viruses. Many of these were G4 viruses.

The CDC is currently taking efforts to combat any effect of this virus in America, by coordinating with public health partners in China, requesting a virus sample, evaluating whether an existing candidate vaccine virus would protect against this virus, and even studying existing antiviral drugs.

There is not yet enough research to solicit the funding needed for a human G4 vaccine. The only way a pandemic would occur is if this strain will mutate to readily transmit between humans, which it has not done yet.

Through Teen Lenses: What do you think about the new G4 virus? Do you believe it could grow into a global concern?

“As of now, the G4 virus does not pose a threat as a global pandemic. Due to Covid-19, China has already taken many precautions in terms of food production and release, and during this time the chances of pig to human transmission is very low. Additionally, with their strict quarantine guidelines, even if the virus were to mutate to allow human to human transmission, it is very unlikely for the virus to spread. However, China does have a large population, and it is difficult to keep the entire country in check at all times. Following our current global pandemic, G4 may become the next, if the current regulations aren’t properly enforced. However, China now understands how to properly combat a fast-spreading virus and they already acknowledged that the G4 virus exists, so I don’t think the G4 will ever reach a global scale.” Ridhi Pendyala, 15, Sophomore at Thomas Jefferson High School for Science and Technology, Centreville, VA
“The G-4 virus could potentially become a global concern looking at how many similarities it has to the Coronavirus. They both started in animals and slowly started mutating to infect humans. Looking at what happened with COVID-19, we should definitely prepare for a possible pandemic, instead of approaching it unreadily.”  Anonymous, 14, Sophomore at Thomas Jefferson High School for Science and Technology, Ashburn, VA
“For the past few months, we’ve all been impacted by the tremendous negative effects of the global coronavirus pandemic and life has essentially come to a halt. Taking extra precautions to sanitize surfaces, cover mouths and noses, and social distance have become the daily norm as infection rates continue to rise in parts of the world. After what has happened, can we be too careful about upcoming virus threats? Is it too rash to presume the worst and spend millions of our budget to research and prevent a virus that may not even post a threat? I do believe that taking the initiative to begin further investigation about the long term possibilities of the G4 virus is vital in suppressing another possible outbreak and bringing life to another grinding standstill.” Harini Ramaswamy, 14, Sophomore at Thomas Jefferson High School for Science and Technology, Arlington, VA


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