Yes, I know about the flu mist. I was going to address it as part of the fourth point which I mentioned earlier (in my list of points to cover): which lines of defence does the body have.
In short: vaccination activates the body’s last line of defence, which normally is only triggered when the virus has already broken through the earlier lines of defence. So vaccination is unnatural in the sense that normally, the other lines of defence are activated earlier than the last line of defence, but with vaccination, the last line of defence is activated first, without ever activating the earlier lines of defence.
The earliest line of defence is when the virus is absorbed in the layer of mucus that covers various mucous membranes (nose, mouth, trachea and so on). The body starts attacking the virus, and “pre-activates” the other lines of defence, just in case the virus breaks through this first line.
The “flu mist” consists of viruses or virus particles that are very similar to the ones that are injected when you are vaccinated. The “mist” is inhaled, absorbed by the mucous layers, and thus activates the first line of defence. It’s much more natural than vaccination.
Up to now, the problem with this “mist” has always been the dose. It is very, very hard to ensure that the right amount of virus particles is absorbed by the mucous membranes. It must not be too few, because then the first line of defence is not triggered enough, and you are still not protected afterward. It must not be too many either, because then you risk inflammation of the mucous membranes and potentially feeling very, very ill for a week or so.
This has been an extremely promising idea since at least 1970 or so. We just could not apply it to practice. It’s only very recently that they (“they” being “big evil pharma”) managed to get the dose right, in a reproducible way. And only for a very limited number of viruses.
It is hoped (and, in fact, expected) that progress in medical treatment/prevention methods will allow us to use the “mist” method for an ever increasing number of diseases in the next 10 to 20 years. Vaccination will probably still be needed for a number of diseases, but much less than today.
For more information, read the Wikipedia article about LAIV.