It's a virus that's easily transmitted from person to person through aerosolized droplets from saliva and other body fluids, ... It is unlike anthrax in that it can be transmitted from person to person and not just a danger by a direct contact.
It's a bit of muted good news, in that we're going in the right direction, but the sobering news is we have a long way to go.
If we could identify what that factor is -- and there's no guarantee we will, but if we can -- then one could direct your vaccine to elicit a response of that particular factor that is protecting them.