The measles, mumps, rubella (MMR) vaccine protects healthcare professionals against three diseases and is administered in two doses. Vaccination is recommended in the event of measles outbreaks. The vaccine may be mandatory in some facilities, depending on the populations the facilities work with. Titer testing can be performed on individuals who are unsure of their immunity status against the disease, as prior exposure to the disease also provides immunity. Of course, there are also contraindications to the vaccine, such as pregnancy, allergies, and other cases. Generally, healthcare facilities require vaccines to protect patients, healthcare professionals, and the facility itself.