A student enters Boelter Hall at University of California, Los Angeles on Thursday. Hundreds of students and staff at two Los Angeles universities, including UCLA, have been placed under quarantine because they may have been exposed to measles and either have not been vaccinated or cannot verify that they are immune, officials said Thursday.

A student enters Boelter Hall at University of California, Los Angeles on Thursday. Hundreds of students and staff at two Los Angeles universities, including UCLA, have been placed under quarantine because they may have been exposed to measles and either have not been vaccinated or cannot verify that they are immune, officials said Thursday.