Censored H5N1 Bird Flu Studies: Much Ado About Nothing?

Why we might have all freaked out for the wrong reasons.

Workers place dead chickens into plastic bags after they were killed at a poultry market on December 21, 2111 in Hong Kong, Hong Kong. 17,000 chickens were culled at a poultry market on Wednesday after a chicken carcass tested was positive for the H5N1 strain of bird flu virus. (Photo by ChinaFotoPress/ChinaFotoPress via Getty Images)

Jun 5, 2012

You may have heard the hubbub surrounding two different studies on H5N1 —aka Bird Flu—recently conducted in Wisconsin and The Netherlands. The researchers in both cases put the virus through a series of mutations in order to better understand how it may eventually find itself in humans. The National Security Advisory Board for Biosecurity decided this was a potential boon to bioterrorism and recommended Science and Nature hold off publishing the papers.

After much arguing in the science community, Nature finally published the paper from the University of Wisconsin-Madison this May (the Netherlands study is currently going through edits at Science HQ).

The results were reassuring: While the researchers managed to learn quite a bit about Bird Flu and how it works, it’s clear the controversy was overblown and ultimately the public has little to fear from H5N1.

In fact, if you read the paper with a careful eye, you’ll see it does more to calm nerves about the potential spread of the virus than fear-mongering headlines would lead you to believe. TakePart asked Vincent Racaniello, a virologist in the Department of Microbiology and Immunology at Columbia University, to help us take a look at the study and understand the truth outside of the controversy:

H5N1 isn’t capable of passing from human to human yet.

The entire premise of the study was to see how many times the current virus would have to mutate in order for it to infect people through the air. Currently, Bird Flu has had outbreaks globally in poultry and wild birds. There have been a few human infections and deaths, but when it does manage to infect a human, it can’t spread.

“That’s unique. Could it ever transmit? That does not appear to happen among people who are infected with H5N1 as far as we know,” says Racaniello.

It took at least four mutations to get the virus to transmit through the air—in ferrets.

A few articles have said the virus is “one mutation away” from infecting humans. This is simply not correct.

“That’s pretty scary,” says Racaniello, “but the paper is very different from that.”

In fact, in order to make the H5N1 able to transmit through the air, the researchers first attached it to the highly transmissive H1N1 gene, which you may remember as Swine Flu.

After making the H1N1-attached Bird Flu mutate four times, the scientists were finally able to create a version that would become airborne and spread from ferret to ferret. But even then, the virus was still a bit of a wimp.

The ferrets were fine.

The new transmissible version of the virus was good at “infecting” the animals.

“But the ferrets don’t get sick. The virus just replicated,” Racaniello says. “This works in ferrets, but who knows what it would do in people. It could mutate even more and become something that eventually makes us sick. It might not transmit at all. Animals are not meant to be predictive.”

In fact, he says, in order to be transmissible in humans Bird Flu might have to change so much it could mutate itself out of existence.

During the study, the researchers accidentally made the virus unstable and incapable of infecting animals at all.

The most interesting and unexpected result of the study was the fact that early mutations made the virus unstable. It broke down inside the ferret’s noses and couldn’t grow or spread. The mutation happened in a region of its DNA that turns out to be important for allowing the virus to enter foreign cells.

“The implication is that in order to be transmitted, the virus has to be very stable. This was anticipated by no one. This is making people think in a whole different way about transmission,” says Racaniello.

In other words, the study indicates a possible new way to stop all viruses from spreading.

“They have made an incredible advance in that way. A lot of biologists will look at this and get ideas,” he says.

It’s OK, there’s already a vaccine.

Regardless of what the second paper may reveal when it’s released, there’s little reason to be concerned about Bird Flu’s potential adaptation and spread among humans. Virologists have been tracking H5N1 since the 1990s and have already developed a vaccine to work against it.

The reason Swine Flu had such a devastating impact was because it surprised everyone and, as a result, took six months to release a vaccine. If—and that’s a big if—Bird Flu eventually learns how to move among humans, we’re prepared to stop it in its tracks.

The bottom line, says Racaniello, is “it was all nonsense to be crazy about this.”

Show Comments ()

More on TakePart

Aaron Neville: Why I Take Part in Rebuilding New Orleans