Wednesday, December 3, 2014

Ebola Probably Won't Go Airborne Anytime Soon

It turns out the talk about Ebola going airborne is... just that. Talk. For a virus to go airborne, or gain any function for that matter, it must undergo a series of profound mutations. For it to undergo these mutations, it must be able to mutate. And this is where we're safe: Ebola is a remarkably stable virus. Claims of sloppy replication are, mostly, misguided: yes, viral polymerase IS sloppier than human polymerase, but this is not specific to Ebola. And the mutations that HAVE occurred in Ebola since its discovery in 1976 have been silent 97% of the time. Ebola is nothing like the Flu, with a mutation rate so high we need a new vaccine every year. Add to that the evidence that Ebola is an ancient virus, and has been allowed the chance to mutate for millions of years, and the argument for a flying virus starts to make less sense.

Not gonna happen.
And even if Ebola DOES go airborne, there is evidence to suggest it will be attenuated. A study conducted by Fouchier and Kawaoka, published in 2012 in Science, has shown that, while it is possible for a virus to become airborne (and the requirements are somewhat quantifiable), the viruses that have been made to do so in the lab have lost their ability to kill. I.e., a gain of function is accompanied by a loss of "function." This would make sense, as the many changes that must occur in the virus's genome are likely to interfere with the function of the virus as a whole.

Overall, we shouldn't be to scared. Of that, at least.

-Matthew Billman

Sources:
http://www.cdc.gov/vhf/ebola/pdf/mutations.pdf (primary)
http://www.virology.ws/2014/09/18/what-we-are-not-afraid-to-say-about-ebola-virus/
http://www.virology.ws/2012/03/01/influenza-h5n1-is-not-lethal-in-ferrets-after-airborne-transmission/
http://www.virology.ws/2012/06/21/influenza-h5n1-virus-versus-ferrets-round-two/
http://www.sciencemag.org/content/336/6088/1534.full
http://www.vox.com/2014/9/19/6543157/ebola-is-unlikely-to-go-airborne

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