Virus transmission map
A graphic generated by Nextstrain shows how different variants of the SARS-CoV-2 coronavirus have spread around the world. Purple streaks show where the virus was transmitted from China, green and yellow-green streaks show transmission from Europe, and red streaks show transmission from the United States. (Nextstrain.org Graphic)

Is the coronavirus behind COVID-19 turning into a more insidious pathogen? Or are such claims overblown?

A fast-moving debate over virus evolution illustrates how not-yet-vetted reports about the course of the coronavirus outbreak can go, um, viral — and how important social media channels have become in the global discussion of the science behind the pandemic.

The nature of SARS-CoV-2, the virus that causes COVID-19, is of such great interest because the disease is so deadly and disruptive: As of today, Johns Hopkins University reports nearly 3.7 million confirmed cases around the world, with a global death toll of more than 250,000. The United States accounts for 1.2 million cases and 71,000 deaths so far, and that toll could double before the worst is over.

Every day, several hundred new studies about SARS-CoV-2 and COVID-19 — most of which haven’t yet gone through the traditional peer-review process — go online, to face scrutiny by researchers and a wide swath of the general public.

One study got more than the usual traction today: The research project, led by scientists at Los Alamos National Laboratory and the University of Sheffield, looked at the way 14 variants of the virus have spread across the world.

Coronavirus Live Updates: The latest COVID-19 developments in Seattle and the world of tech

The resulting paper was filed to the BioRxiv preprint server last week but has not yet been peer-reviewed. It concluded that one particular variant known as D614G is “of urgent concern.” That variant, a descendant of a form of the virus that started out in China, began spreading in Europe in early February and eventually made the leap to other parts of the world.

“When introduced to new regions, it repeatedly and rapidly becomes the dominant form,” the researchers noted.

The concern was that the virus had evolved to become more transmissible, and that interventions aimed at curbing the pandemic might not be as successful as hoped. People who survived a bout with one variant of the virus might still fall prey to the increasingly dominant variant, the researchers said.

“We cannot afford to be blindsided as we move vaccines and antibodies into clinical testing,” lead study author Bette Korber said in a Facebook post quoted by the Los Angeles Times. “Please be encouraged by knowing the global scientific community is on this, and we are cooperating with each other in ways I have never seen … in my 30 years as a scientist.”

It didn’t take long for the scientific community to start assessing the team’s conclusions — and the way they were being reported to the general public. Cornell University virologist Brian Wasik pulled no punches on Twitter:

And he wasn’t alone. Columbia University’s Angela Rasmussen said the report made her blood boil. “There is no evidence that the dominant strain is such because it is ‘more contagious,’ ” she tweeted.

READ  Covid-19: how does it affect pregnancy? – podcast

Harvard University’s Bill Hanage laid out an alternate explanation in his own Twitter thread, posted way back on Friday. He argued that D614G might have become the dominant variant of the virus simply because of a metaphorical roll of the dice:

You’ll have to read through the entire 15-tweet thread to find out how Hanage uses data from Washington state to back up his view. Here’s his bottom line: “Right now there are better ways of fighting the pandemic than worrying about different strains defined by one non-synonymous SNP. … If anyone who does not know what it is already googles ‘non-synonymous SNP,’ I will be delighted.”

But wait … there’s more: This afternoon brought a more ambiguous verdict from Trevor Bedford, the epidemiologist at Seattle’s Fred Hutchinson Cancer Research Center who started tracing coronavirus evolution back in January. Ever since then, he and his colleagues at Nextstrain and the Seattle Flu Study have been comparing genetic fingerprints from viral variants to map how they’re spreading globally.

Bedford said there’s some evidence to back up the claims made by Korber and her colleagues, but that the case is “far from conclusive.” He also stressed that D614G doesn’t appear to be more dangerous than the other variants, even if it’s currently more dominant. Here’s the full thread:

For folks who are willing to follow these threads closely, there’s a payoff that goes beyond the immediate questions about transmissibility and variations in the virus. With the right kind of perspective, the combination of raw research and social-media assessment can provide a look at how the scientific sausage is made, analogous to the way those old-fashioned “Visible Human” figurines provided literal transparency for anatomy class.

READ  The Guardian view on the UK’s Covid-19 response: confused and hesitant | Editorial

Bedford himself marveled over how quickly things have changed during a session at February’s annual meeting of the American Association for the Advancement of Science in Seattle.

“It’s been a really interesting way that science has been proceeding, to have it being very rapid and open as it’s done, not just waiting a year later for the paper to come out,” he said. “This mirrors generally what’s been happening with scientific communication surrounding the epidemic, where everything’s kind of been flipped around. … It’s been an amazing coming together of scientists around the world.”

The past few weeks have demonstrated how messy the scientific process can be, but they’ve also demonstrated how its error-correction mechanisms work. And that’s a good thing, even if it means dealing with some turmoil on Twitter.





READ SOURCE

LEAVE A REPLY

Please enter your comment!
Please enter your name here