On June 30, 2020, several media outlets, including BBC News, reported on a new variant of H1N1 swine flu that “has the potential to become a pandemic.” These reports come from a June 29 scientific article in the Proceedings of the National Academy of Sciences (PNAS). Using a large amount of data collected from pigs in China, along with animal experiments and epidemiological observations, the researchers concluded that a variant of the virus responsible for the 2009 swine flu pandemic is increasingly prevalent in pigs and can be transferred to the humans. It has, they say, the potential to cause a deadly human pandemic.
Generally speaking, two things are required before an animal-derived virus can cause a pandemic. First, the virus, although hosted by an animal such as a pig or a bird, must develop the ability to transfer and replicate within a human body. Second, the virus must be able to spread from one human to another. As of this date, researchers have observed this strain in humans working near pigs, but there is no evidence of the latest human-to-human spread.
What is swine flu?
The 2009 swine flu pandemic was caused by a form of the A (H1N1) influenza virus pdm09, which formed, according to a review in the journal Scientific Reports, “as a result of a new assortment among avian flu viruses , human and swine. “Although the virus spread rapidly throughout the world, it was not particularly lethal. This lack of lethality was due, in part, to the fact that, according to the Centers for Disease Control and Prevention (CDC), “nearly a third of people over the age of 60 had antibodies against this virus, probably due to exposure to an older H1N1 virus earlier in their lives. “
Scientists monitor the genetic drift and evolution of countless influenza viruses in an effort to create an effective influenza vaccine every year, but they have also been monitoring H1N1 variations in animal populations due to the risk that an most virulent form of this influenza virus. . The PNAS June 2020 report represents this latest effort.
What is this new swine flu?
In general, RNA viruses like influenza mutate rapidly compared to DNA viruses. Viruses, which are mainly made up of small fragments of genetic material, can sometimes combine with other viruses and mix genetic material with each other. Over time, mutations that are advantageous to the virus become dominant, occasionally giving it new properties that could make it capable of surviving in other host organisms such as humans.
From 2011 to 2018, PNAS researchers collected about 30,000 pig nasal swabs and identified more than 100 strains of swine influenza. Their work showed that, as of 2016, a modified form of H1N1, called “G4 EA H1N1”, became the dominant strain in these pigs. This is potentially problematic, the researchers argued, because the so-called “G4 genotype” of H1N1 is capable of binding “to human-like receptors,” can easily replicate in cells of human airways, and can be transferred through the air.
In fact, the researchers found that 10 percent of individuals (out of 338 samples) working near pigs tested positive for G4 EA H1N1, indicating that the virus “has acquired increased human infectivity.” This is evidence that this new swine flu can jump between pig and human, but it is not evidence of transfer between humans.
Will this new swine flu become the next pandemic?
Because the virus can be easily transferred from pig to human, according to PNAS researchers, the fear is that the virus has had, and will continue to have, repeated opportunities to adapt while housed within the body of an infected human. Such adaptations could lead to the ability to transfer the virus from person to person, either through direct contact or airborne transmission. If that happens, the risk of a pandemic, according to the authors, is further increased by the fact that the world population has very low natural immunity to type G4 influenza viruses.
CDC’s Fauci, at a hearing in the US Senate on the COVID-19 epidemic, told lawmakers that “the possibility that I may have another swine flu outbreak like the one we had in 2009” is real. , but that “it is something that is still present at the examination stage” and “it is not an immediate threat.” In a statement given to media like CNN and BBC, a spokesperson for the World Health Organization said:
The Eurasian avian-type swine flu virus is known to circulate in the Asian swine population and can infect humans sporadically. Twice a year during influenza vaccine composition meetings, all virus information is reviewed and the need for new candidate vaccine viruses is discussed. We will carefully read the [PNAS] role to understand what’s new.
What’s next According to the PNAS team, there are measures that could greatly reduce the possibility of a pandemic. “Control of the predominant G4 EA H1N1 viruses in pigs and close monitoring in human populations, especially workers in [the] the pig industry, “they wrote,” should be implemented urgently. “
