By the same lead author that published the pig Ebola transmission paper comes a new publication examining airborne transmission among primates. In these, Ebola did *not* spread between non-human primates (NHPs) via air. I sent an email to the PI to comment; will update the post if he responds, but in the meantime, some money quotes directly from the publication:

"One experiment reported contact free transmission between infected NHPs to one uninfected NHP although cross-contamination due to husbandry practices could not be ruled out with certainty26. Interestingly, EBOV infected swine transmitted the virus to naïve NHPs over a 0.3 meter buffer zone that prevented direct contact between the 2 species27. ...However, airborne transmission in natural outbreaks cannot be a common occurrence and is possibly insignificant by the account of several reports4, 9, 28, 29, 30."

and

"The presence of transmission in the pig-NHP experiment and not the NHP-NHP experiment, both performed under similar conditions and environments, could be explained by the fact that EBOV disease in pigs is respiratory in nature with high amounts of infectious particles present in the oro-nasal cavities in the symptomatic phase of the disease which provided an opportunity for release into the environment35. On the receiving end, NHPs are known to be susceptible to lethal EBOV infection through the respiratory tract24, 27, 31 putting the onus of the transmission on the ability of the source to shed infectious particles."

Translation: even though previous reports in primates had suggested the potential for airborne transmission, other factors couldn't be ruled out, and epidemiologically, it's insignificant. In the experiments they did, pigs just handle Ebola differently than primates (as I mentioned here), and so make them more likely to spread the virus via a respiratory route.

Significance: No airborne transmission between primates in this controlled experiment, strengthening the evidence that Zaire ebolavirus isn't a risk in this manner. So Donald Trump, you can stop freaking out now.