In the days and weeks since the measles started popping up in B.C.'s Lower Mainland, doctors and pharmacists say they've seen a spike in teenagers and adults asking for the vaccine.

One Metro Vancouver pharmacy has provided up to 30 shots in a single day, according to the B.C. Pharmacy Association.

The best way for anyone ensure they're protected against the disease is to have two doses of the MMR (measles, mumps and rubella) vaccine, according to Vancouver emergency physician Dr. Afshin Khazei.

While one dose offers significant protection in the short term, that benefit will drop off over time. There is no risk from an extra dose.

"Our approach is: if in doubt, we give a booster," Khazei said.

To date, there have been 15 confirmed measles infections in the Vancouver Coastal Health region.

Though new cases continue to pop up, officials say anyone who's already had the measles should be safe. Those born before 1970 are also assumed to be immune, because the majority of people contracted the disease and developed immunity in those earlier years.

More measles cases confirmed by Vancouver Coastal Health (Sean Holden/CBC)

For everyone else, it depends on your age and where you grew up.

People who were born in B.C. after 1994 generally would have received two MMR doses, but others will have to check their immunization records.

If those records aren't available, health officials say the safest option is to get a booster.

"If there was registration and a centralized registry that we could access, we could possibly avoid giving them an unnecessary dose," Khazei said.

He acknowledged that there is plenty of misinformation out there about the vaccine, including the thoroughly debunked theory of a connection to autism.

Despite social media chatter to the contrary, recently vaccinated people do not "shed" the virus, and there's no risk of them spreading the disease, Khazei said. Vaccinated people also cannot act as "carriers" of the measles.

Moojan Azizi was born in Iran and can't recall his immunization history. His mother is no longer alive to ask, so he received an MMR booster shot on Tuesday. (Sean Holden/CBC)

As for potential side effects, "The risk of having a serious adverse reaction to an MMR vaccine is about one in a million," Khazei said.

On the other hand, the risk of serious complications from the measles is much higher, he added. Those complications can include encephalitis (one in 1,000 cases), pneumonia (one in 10 cases) and ear infections (one in 10 cases).

About one in every 3,000 measles patients will die from respiratory or neurological complications, according to the province.