Why are you assuming most in Europe and the US would be vaccinated? If it's not life-threatening, most people won't bother. Most people don't even bother to get the flu vaccine each year. I got a Hep B vaccination when I went to South America, but I never got around to going back for the booster shot. I'm a firm believer in vaccines, and my children will certainly get all of theirs on schedule, but I'm unlikely to get a cold vaccine for myself - and suspicion that the vaccine isn't really good for me in the long run would be part of my reason, beyond laziness.