Health authorities are on the alert after measles broke out at some universities. Measles is typically a childhood disease, and this is the first time a group of university students have contracted the disease since it was officially declared eliminated in 2006.
Since the first case was confirmed on April 8, 12 students -- 11 at Kookmin University and one at Kwangwoon University -- have definitely been infected, the Korea Centers for Disease Control and Prevention said on Tuesday.
By Monday 77 students were suspected of having contracted measles, but 11 were confirmed as being clear of the disease and the rest are undergoing tests.
Measles causes high fever, cough, runny nose and a rash and can lead to complications such as diarrhea, pneumonia, encephalitis and more rarely, death.
To prevent a further spread, vaccination will start from Thursday, targeting students and faculty at Kookmin University, the KCDC said.
Administering the vaccine within 72 hours to people who have been exposed to measles may prevent them from developing the disease, it added.
Over 95 percent of Koreans are vaccinated against measles, but the number of patients has been rising.