Dr. Cillian De Gascun:

I might add to that, albeit my point is not specifically about air travel. Recently, a paper has been highlighted - people have probably seen it mentioned in the media - discussing a novel variant of the virus from Spain that has travelled around Europe. From a virological perspective, it highlights how interconnected we all are. Fortunately, there is no evidence that the virus is necessarily more transmissible or virulent, but it demonstrates nicely that the virus will spread readily if given the opportunity. Obviously, travel facilitates that.