Japan may have a smaller population than the US, but the arguement for vaccines would stem more from population density. Which you can hardly argue that the US has a lower population density than Japan. Both on average and in concentrated areas.
If you're vaccinated the dangers of a common communicable disease that is very succeptible to vaccines, which measles 100% is, shoudn't be the big problem its presented as.
Daniel Salmon, the director of the Institute of Vaccine Safety at Johns Hopkins University, told ABC News that the involvement of a foreign individual or an American who recently traveled to a foreign country is "typically" how measles outbreaks start in the U.S.
"Most of the time we don't have indigenous transition of measles" in the U.S., Salmon said. "We do right now, but once this outbreak is taken care of, we'll have no more measles in the U.S."
