Protecting babies from measles: What parents need to know

Pediatrician Dr. Charles Goodman vaccinates 1-year-old Cameron Fierro with the measles-mumps-rubella vaccine, or MMR vaccine, at his practice in Northridge, Calif. (AP /Damian Dovarganes)

With an outbreak of measles in the Toronto area, and bigger outbreaks in California and several other places around the world, measles is definitely on the minds of many parents with young children.

For parents with kids who are not yet immunized or too young to get the shots, the outbreaks are particularly concerning. Measles is particularly dangerous to young children, who can develop dangerous complications, such as pneumonia or encephalitis.

Here's a look at some of the questions parents might have:

I'm worried about these outbreaks. Should we ask our doctor to give the measles vaccine to our baby early?

The measles vaccine is contained in a vaccine called MMR (measles, mumps, rubella), or MMRV (measles, mumps, rubella, varicella).

The current recommendation in Canada is to give the first dose of the vaccine when children are between 12 and 15 months of age. The second dose can be given any time after 18 months of age, though typically it's offered when the child is 4 years old, before they begin full-time school.

But if you are living in an area that is in the middle of a measles outbreak, the vaccine can be given to babias early as six months of age. The same is true if a baby will be travelling to a region where measles is a concern. Currently, those areas include California, the Philippines, Vietnam, and parts of China. Here's more on current measles hotspots.

Babies under six months of age should have some immunity from measles passed on through the placenta if the mother was fully vaccinated.

Is it dangerous to give the vaccine early?

The main reason that doctors wait until babies are a year of age before the first dose is it is more likely to work on an older baby. The immune system of a 12-month-old is more mature and thus more likely to create the appropriate antibodies in response to the vaccine.

Most of the research on the effectiveness of the vaccine has been in children over 12 months of age, but there is no reason to believe that younger babies are any more likely to have an allergic reaction or a side effect from getting the vaccine early.

What happens to the other doses if my baby gets the vaccine early?

If a baby is given the measles vaccine before 12 months of age, they should still receive the routine two doses: one on or after the first birthday, and another at 18 months or older, to ensure they develop long-lasting immunity. (Here are some tips for reducing the needle pain and anxiety of vaccinations.)

My child has had only had one dose. How protected are they?

Even with just one dose, a child has good protection against measles: the first dose has an efficacy of about 85 to 95 per cent. The second dose is given as a booster and to help those who didn’t mount much of a response to the first dose. After the second dose, the vaccine's efficacy approaches 100 per cent.

What should I do if I think my baby has been exposed to measles?

If your baby hasn't been vaccinated and you have good reason to believe they have been exposed to the virus, you should see a doctor right away. Call first before bringing your child to a doctor's office or medical clinic, to avoid risking exposing others.

Babies older than six months of age can be protected from full infection if they are given the MMR vaccine within 72 hours of their exposure to the virus. This is called "post-exposure management" and has been shown to protect or at least reduce the severity of the illness.

There is also something called measles immunoglobulin (or immune globulin) that can be offered within six days of measles exposure to babies under six months old, to pregnant women, or to those who can't have the measles vaccine. Unlike the vaccine, which uses a weakened version of the virus, immune globulin contains antibodies taken from donated human blood.

A doctor can decide which course of action is best.

How will I know if my child is infected?

Unfortunately, it will be very hard to tell at first, since it can take up to 10 days after a child is exposed to measles before they begin to develop symptoms. The illness typically begins like a cold with symptoms that include runny nose and a cough, mild fever, and red, swollen eyes. You may also notice small white spots in the baby's mouth.

Three or four days after these symptoms, red spots will begin to appear on the child's face, neck and backs of the ears and the fever will likely rise. The rash will then spread down over the body and develop a bumpy, itchy texture.

The child will need to be isolated while they are ill because measles is highly contagious even before the rash begins and for four days afterwards.