The Fraser Health Authority is warning residents in six communities of a measles outbreak in low-immunized areas.
Residents in Abbotsford, Mission, Chilliwack, Agassiz, Harrison Hot Springs and Hope are encouraged to contact their doctor if they suspect they have been exposed to the virus or have developed symptoms.
The organization says two cases have been confirmed in a Chilliwack school and dozens of suspected cases are being investigated.
The Public Health Agency of Canada is contacting the affected families directly to offer treatment.
Fraser Health is advising those who have been exposed to the virus to refrain from travel until they have been cleared by the federal agency.
The best protection against measles is two doses of the vaccine, which is free to all those born in or after 1957.