Immunization is not compulsory or "forced" in Canada, but we do have regulations that help ensure that as many people as possible are protected by vaccines from the diseases they prevent. Some provinces require certain vaccines to be given before a child can enter school, but these are not mandatory in the usual sense of the term. Rather, parents (or children, if they are old enough to give consent) are required to declare a choice of whether to have their child (or themselves) immunized or not. If they choose not to, the child may be told that he or she must stay home from school if there is an outbreak of disease. This rule is designed to keep unimmunized children from getting sick and to keep the outbreak from spreading. School entry regulations also give parents an opportunity to bring their child's immunizations up to date. Health care workers may also be required to have certain vaccinations, such as hepatitis B vaccine and an annual 'flu shot'. If they refuse, they may be required to stay away from work during an outbreak. This practice protects their patients, who could be in grave danger if they became ill with a communicable disease.