On June 30, 2020, several news outlets, including BBC News, reported on a new variant of the H1N1 swine flu that “has the potential to become a pandemic.” These reports stem from a June 29 scientific paper in the journal Proceedings of the National Academy of Sciences (PNAS). Using a trove 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 humans. It has, they say, the potential to cause a deadly human pandemic.
Broadly speaking, two things are required before an animal-derived virus can cause a pandemic. First, the virus — though hosted by an animal such as a pig or a bird — must evolve the ability to transfer to, and replicate inside of, a human body. Second, the virus needs to be capable of spreading from one human to another. As of this date, researchers have observed this strain in humans who work in proximity to pigs, but there is no evidence of the latter human-to-human-spread.
What Is Swine Flu?
The 2009 Swine Flu pandemic was caused by a form of influenza A virus — (H1N1)pdm09 — that formed, according to a review in the journal Scientific Reports, “as a result of re-assortment between avian, human, and swine influenza viruses.” Though the virus spread rapidly around the world, it was not particularly lethal. This lack of lethality was, in part, thanks to the fact that, according to the Centers for Disease Control and Prevention (CDC), “nearly one-third of people over 60 years old had antibodies against this virus, likely from exposure to an older H1N1 virus earlier in their lives.”
Scientists monitor the genetic drift and evolution of myriad influenza viruses in an effort to create an effective flu shot each year, but they have also been monitoring variations of H1N1 in animal populations due to th