Health officials in New Brunswick have confirmed two more cases of measles in the Saint John area, bringing the total number of cases to 11.

The new cases were confirmed late Tuesday and are both linked to a previous confirmed case at Kennebecasis Valley High School.

On Friday, public health officials issued a directive that staff and students at the high school must receive a measles booster shot if they want to continue working and studying at the school.

The phone at a north end Saint John pharmacy is ringing off the hook as pharmacists are fielding call after call about the measles outbreak.

“We're mainly, I think, receiving phone calls, and lots of them, with people that are concerned and trying to get information on whether they should be vaccinated,” said pharmacist Ryan Kennedy.

As of Monday, more than 950 students and staff had been given the vaccine, and it was still available to the final few people who had not received it.

The New Brunswick government says measles can be prevented with a vaccine and that most people are protected after two doses of the vaccine. In New Brunswick, the vaccine that protects against measles, mumps, rubella and varicella is free of charge for babies aged 12 and 18 months.

Dr. Jennifer Russell, New Brunswick’s chief medical officer of health, says over 2,000 people may have come into contact with one or more of the 11 confirmed cases.

“We are currently addressing all of the contacts of all the confirmed cases by offering immunization in that 72-hour window when it is effective,” Russell said.

The measles virus is transmitted through the air or by direct contact with an infected person. Measles can be more severe in adults and infants and can lead to complications.

Early symptoms of the virus may include fever, cough or tiny white spots in the mouth.

Within three to seven days, a red rash will appear, first on the face and then spreading to the body, arms and legs.

Health officials are asking anyone who has these symptoms to call ahead before visiting their doctor or emergency room, so that necessary measures can be put into place to prevent the spread to others.

Public health doesn't provide pharmacies with the MMR vaccine, Kennedy says they can help if they're called on.

“I think that there is a chance that if they determine that more widespread vaccination is needed that they'll get us involved, but for the time being, that's not the case,” Kennedy said.

Public health says they're asking anyone who came into contact with the affected people to stay at home and watch for symptoms.

District school officials have also cancelled a number of planned out-of-province class trips at two other schools in the district as a result of the measles outbreak.

About 150 Grade 8 students at Rothesay Park and Harry Miller Middle schools won't be visiting Quebec City as planned.

In a statement, the school district says it was decided not to take an unnecessary risk.

“The schools are working with the tour provider who is still in the process of cancelling venues, accommodations and transportation. While we understand that our families and students are disappointed, families have been largely cooperative, and many parents have already reached out to the schools to offer suggestions and help in arranging alternate activities for the students."

Health officials reiterated that the best way to protect yourself and others against measles is by being vaccinated.

With files from CTV Atlantic's Laura Lyall and The Canadian Press