Students waited in long lines at the university's Tang Health Center to get a MMR vaccine for measles, mumps, and rubella.
Even if students have had the vaccine, the health center is advising they get an additional dose.
There are seven confirmed and 13 suspected cases of mumps on campus. By contrast, the City of Berkeley has had just six cases in the past two decades.
The mumps virus is spread by saliva or mucus. It is typically associated with young kids. Symptoms include fever, headache, and swollen glands.
The Associated Press contributed to this story.