2020 update: So many were trying to compare the US and South Korean reactions to COVID-19. My response: It is ridiculous to compare them. South Korea has had a number of viruses come through, pollution from China. Back in 2015, when MERS came through, many Koreans were reaching for their masks. Masks were so prevalent even 5 years ago that I used them as a gag, putting one on a birthday gift. From what I have heard, there are still debates in the USA about the effectiveness of masks.
2015 comments: South Korea is in a frenzy now because of the Mers virus...
I don't know how seriously to take it, I seem to remember similar scares--Swine flu, mad cow disease, bird flu, SARS, Ebola, foot-and-mouth disease, West Nile virus... now Mers...
Just in case, I bought a mask...