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Why you shouldn't panic about the swine flu strain with 'pandemic potential'

Headlines and social media suggest we're on the verge of another pandemic, but they leave out important context.

Jackson Ryan Former Science Editor
Jackson Ryan was CNET's science editor, and a multiple award-winning one at that. Earlier, he'd been a scientist, but he realized he wasn't very happy sitting at a lab bench all day. Science writing, he realized, was the best job in the world -- it let him tell stories about space, the planet, climate change and the people working at the frontiers of human knowledge. He also owns a lot of ugly Christmas sweaters.
Jackson Ryan
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A new strain of influenza has sent social media into a bit of an apocalyptic panic. 

Getty/China Photos

The coronavirus pandemic isn't even close to being over, and, if you read the latest headlines, there's a potential new pandemic right around the corner. This one's caused by influenza -- the virus that causes the flu -- and the culprit was discovered circulating in pigs in China. Even the Fonz himself was concerned

But the headlines are overdoing it a little, and the panic is unnecessary. Let's set the record straight. 

Various reports about a study published Monday in the journal Proceedings of the National Academy of Sciences have sent social media into a bit of a panic with apocalyptic endgame scenarios, worrying many that we're staring down a double pandemic that will end it all and have us running to our bunkers in the hills. Some posts suggests people already believe this new virus is emerging and spreading through China. 

The study examined pig populations in China from 2011 to 2018, taking thousands of swabs from slaughtered farmed pigs and testing them for influenza viruses. The research team discovered a strain that contains genetic material similar to H1N1 influenza, the virus that caused a pandemic in 2009, has become more dominant in Chinese pig populations since 2016. 

Researchers showed the strain, dubbed G4, was the major influenza strain in the pig population they tested and that it has the ability to infect human epithelial cells in the airway. It has also infected some farm workers, with around 10% of those exposed to the animals showing antibodies to the strain.

However, the virus has been circulating in swine since 2016 and when jumping to humans it is yet to cause significant illness. It's unclear whether the strain can do that. There's also no evidence it has spread from human to human. For a pandemic to kick off, the virus needs to achieve both these things by picking up new genetic information. 

Could that happen? Yes. Should you panic? Well, no.

"it's something that still is in the stage of examination," said Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, during a senate hearing on Tuesday. "It's not a so-called immediate threat, where you're seeing infections, but it's something we need to keep our eye on."

And although current flu vaccines don't protect against this strain, the next batch could be designed to provide protection if this virus did reach pandemic proportions. But that remains a big if.

Surveillance of influenza strains is a valuable tool for epidemiologists and public health authorities, allowing them to screen vulnerable populations and better understand if the virus is evolving to become more virulent. The researchers suggest G4 should be closely monitored in pigs and in human populations now.    

It's well worth reading Twitter threads composed by Angela Rasmussen, a virologist at Columbia University, and a similar thread by Carl Bergstrom, a biologist at the University of Washington, Seattle. Both break down where some of the misunderstandings come from by detailing the experiments and how they relate to the headlines. 

"The bottom line is that our understanding of what is a potential pandemic influenza strain is limited," Rasmussen writes. "Sure, this virus meets a lot of the basic criteria, but it's not for sure going to cause a hypothetical 2020 flu pandemic, or even be a dominant strain in humans."

"I think the key context is that there are ALWAYS strains out there with pandemic potential," Bergstrom added, via email. "Identifying one is just that—it's identifying something we need to watch. It doesn't much change my estimate of the risk of seeing a pandemic in say the next four or five years."

Reading into 'pandemic potential'

It's important to pull back the curtain a little here, too. The journal this work was published in, PNAS, sends out a weekly list of embargoed journal articles it will publish in the following seven days to media. In this week's email, there was reference to a  study headlined with "Swine influenza virus with pandemic potential." It's a fairly eye-catching headline and not exactly incorrect, but it's written to attract media to get interested in telling the story of the research.

And that's where some of the panic begins. The journal article itself references the idea pigs are particularly good "mixing vessels" for flu viruses because they enable different influenza strains to swap genetic information with each other. These swaps could result in viruses that are more likely to infect humans and cause disease. It is the only reference to "pandemic potential" made in the paper.

The journal article exists behind a paywall, so the full seven-page article isn't freely available to the public. A similar situation occurred in May with a paywalled article by New Scientist being dredged up to claim NASA had found a parallel universe where time runs backward. Spoiler: It (sadly) hadn't, and we're stuck with this universe. 

During the coronavirus pandemic, scientists, researchers, the media and the public have had to grapple with an "infodemic," as the World Health Organization calls it. An infodemic is an overabundance of information, both accurate and not so accurate, that makes it extremely difficult to find trustworthy sources. 

Would we have seen the "pandemic potential" flu pick up so much steam if we weren't already in a pandemic that's turned everything on it's head? My guess would be no. It will be important to keep track of this virus -- and other influenza viruses -- so we can better prepare for potential pandemics. But we will also need to remain vigilant when discussing these studies. 

Watch this: How to follow the pandemic with online tools

Added June 30: Links to the Fonz tweet, statement by Fauci.
Added July 1: Correspondence with Carl Begrstrom.