A day after Alberta Health Services announced measles outbreaks in Edmonton, officials said a spike in calls to book immunization appointments had crashed their system, and more people were being brought in to deal with the flood of calls.

AHS said the Health Link line was overwhelmed by calls, and crashed – on Wednesday, officials said more staff had been added to answer phones.

“The high volume of calls was really good in a way, but it was higher than expected and certainly too high to respond in a timely way,” Dr. Marcia Johnson, Medical Officer of Health, said.

Officials also said in Edmonton, extra immunization clinics were being added – but no dedicated measles clinics are planned, unlike Calgary, where a clinic is being set up.

Meanwhile, Dr. Johnson said the top priority for immunizations is infants between 6 and 12-months-old, and unimmunized children, including children who haven’t had their second dose.

In addition, adults born after 1970 should get vaccinated, Dr. Johnson said.

There have been 22 confirmed cases of measles in 2014: 6 in Edmonton, seven in the Central Zone and nine in Calgary.

To book an appointment to be vaccinated, call Health Link Alberta at 1-866-408-LINK (5465).

Infectious disease expert answers common questions about measles

While the number of confirmed cases of the illness has grown in recent weeks, a number of questions have risen; CTV News posed a number of them to infectious disease expert Dr. Lynora Saxinger.

Q: How safe is the vaccination for children under 12 months old?

A: Dr. Saxinger said immunizations for babies under the age of one are uncommon because maternal antibodies are still present in their systems – and while those antibodies protect them from measles, their effectiveness drops over their first year of life, and vaccines would ideally be administered before it’s totally gone.

“If we vaccinate before the maternal antibodies are gone, the vaccine won’t work,” Saxinger said. “The safety data that’s available would be for kids between the ages of six to 12 months, and then all the age ranges all the way up to adulthood.”

Q: How can you tell if a vaccine is 99 percent effective? How do they know that?

A: “They use trials, where they calculate the incidence of the disease, in people who have had the vaccine versus people who have not had the vaccine,” Dr. Saxinger said. “You would call it a proportional reduction in the disease among the vaccinated group.

“A 99 percent reduction is a 99 percent reduction in the number of cases you’d expect in that group of people, compared to people who have not had the vaccine. It’s just a very direct comparison to people who have had the vaccine to people who have not had the vaccine.

“Because measles is so contagious, we get quite high numbers in those early studies.”

Q: Some pregnant women find out they don’t have immunity to measles, is there a way for non-pregnant people to find out if they have immunity?

A: “We find out measles immunity in pregnant and in healthcare workers by a blood test, which can test for the antibody level,” Dr. Saxinger said. “That’s not routinely recommended for the whole population, because if you were born before 1970, you are assumed to be immune, because you would have been growing up at a time when there were measles epidemics every couple of years and you would have had natural infection and immunity, or you might’ve had a shot of vaccine in the 1960s.

“For people born in 1970 and later, when the disease wasn’t so present in communities, you have to have two shots documented.”

Anyone who doesn’t have their vaccination records can contact public health to get those records.

Q: Do you know what percentage of the population the immunity is effective for?

A: Dr. Saxinger said the MMR vaccine is between 95 and 99 percent effective.

“That means that those people would have a protective immune response. One thing that comes up is people that have had the vaccine can still get the disease; we’ve seen that in some of the epidemics in Europe, in Asia and North America, where there are a proportion of people who acquire the disease when it’s circulating in the community who have had shots, and that’s because vaccine effectiveness can drop with time,” Dr. Saxinger said.

Q: How long will it take for the vaccine to be effective once it’s administered?

A: “It is usually thought that you will get good protection from the vaccine after about two weeks,” Dr. Saxinger explained. “That’s about the amount of time it takes for the vaccine strain virus to replicate throughout the body and generate an immune response.”

Q: Is the MMR vaccine mandatory in schools? If not, should it be?

A: “It is certainly recommended strongly, and there are places where if you can’t provide evidence of immunity, the child would not be allowed to go to school during a measles outbreak situation,” Saxinger said.

“The enforcement, I think, is where it becomes more of an issue.

“I do think that, ethically, when we look at reasons you can compel someone to do something for public health reasons, it’s usually said that if something is a benefit to the individual, if there’s good evidence there’s benefit to the individual, if there’s evidence that it is safe, and if there’s evidence that this is the only way to accomplish the goal, that would be ethical justification for something to be mandatory. I think you can make an argument that that could be the case in this scenario.

“You do need a very high vaccination rate in the population, and we haven’t been able to attain that, without having some mandatory element, and also some enforcement of that. I think that’s going to be a topic of some discussion in the next little while.”

With files from Susan Amerongen