All students must be completely immunized in order to attend school. Massachusetts immunization regulations specify minimum immunization requirements for enrollment in school (105CMR 220.00). Those students with documented medical contraindications or documented religious beliefs are the only ones exempt from the immunization regulation. However, any student who is not properly immunized will be excluded from school if there is a vaccine-preventable disease outbreak. The length of exclusion is determined by Department of Public Health guidelines and may vary according to disease.