The Public Health Agency of Canada has released a reminder to Canadians that measles is “serious and highly contagious.”

The notice comes amid a measles outbreak in Vancouver, B.C., after an unvaccinated Canadian child contracted the disease on a family trip to Vietnam. Nine cases of measles have been identified in Vancouver in recent weeks.

“Due to the recent reports of measles, the Public Health Agency of Canada would like to remind Canadians that measles is a serious and highly contagious disease that causes high fevers, coughing, sneezing and a wide-spread painful rash,” the agency said in a statement on Tuesday.

The outbreak in Vancouver has caused widespread concern among caretakers of vulnerable people. A mother in Burnaby, B.C., was frustrated after her son, who was born prematurely last year, was quarantined over fears he contracted measles earlier this month at the BC Children’s Hospital in Vancouver.

Officials stressed Tuesday that the MMR measles vaccine is the best protection against the disease. “Two doses are almost 100 per cent effective in preventing the disease,” the statement said. The vaccine not only protects the vaccinated, but can protect vulnerable members of the population who are unable to receive the vaccine.

“Not everyone in our communities can be vaccinated, including infants, people with certain underlying health conditions, and those undergoing chemotherapy,” the agency said. “These individuals rely on community immunity to protect them from serious diseases like the measles.”

Canadians should ensure that their immunizations are up to date, especially if they plan to travel outside the country, they said.