Winnipeg Free Press - PRINT EDITION

Shot could hurt measles vaccine program: study

  • Print

TORONTO -- A large measles outbreak that occurred in Quebec a couple of years ago is raising more questions about whether babies are getting their first dose of measles vaccine at too young an age.

A new analysis of the 2011 outbreak, which involved a surprising number of children who should have been protected against the virus, suggests giving the first dose of measles vaccine at 12 months may be undermining the efficacy of the vaccination program.

And it raises the possibility a growing pool of vaccinated children may still be vulnerable to infection -- which, if true, could put in jeopardy efforts to eliminate and eventually eradicate measles, one of the authors of the study said.

"This study shows that there is vulnerability in children who receive two doses and we should not overlook that. The reason for that is still unknown. But it is important to dig into this question further," said Dr. Gaston de Serres, an infectious diseases specialist with Quebec's provincial public health agency.

"If we create a vast pool of susceptibles, one day or another it won't be an outbreak of 700 cases like we had in Quebec, but it may be thousands of cases, if not more."

The new study was published today in the journal Pediatrics.

De Serres and colleagues have been mining data from the 2011 high school outbreak to try to figure out why 102 of the 725 children infected caught the disease at all. They had received the recommended two doses of measles vaccine when they were young children.

An earlier study by the same researchers showed that in the outbreak, teens who got their first dose at 12 months -- the time recommended across Canada -- were six times more likely to be infected than those who got their first shot at 15 months of age.

When they published that study, one of the suggestions was that a phenomenon known as "maternal antibody" may have been responsible.

It takes time for the human immune system to develop. But babies survive infancy because they receive antibodies to diseases their mothers have either experienced through infection or been introduced to through vaccination.

Maternal antibodies wane over time. But while they are present, if a baby is given a vaccine made from a live but weakened virus, the maternal antibodies may quell the vaccine virus before it has a chance to induce a strong immune response. Measles vaccine is a live-virus serum.

So immunization programs are planned to try to hit the sweet spot, giving vaccines in time to protect toddlers against threats but not so soon the vaccines won't be fully effective.

It's thought women who had measles would have higher levels of maternal antibodies than women whose immunity was due to vaccination. Most people born before measles vaccination programs began in Canada in the early 1970s would have been infected with the highly contagious virus.

-- The Canadian Press

Republished from the Winnipeg Free Press print edition October 21, 2013 B5

Fact Check

Fact Check

Have you found an error, or know of something we’ve missed in one of our stories?
Please use the form below and let us know.

* Required
  • Please post the headline of the story or the title of the video with the error.

  • Please post exactly what was wrong with the story.

  • Please indicate your source for the correct information.

  • Yes


  • This will only be used to contact you if we have a question about your submission, it will not be used to identify you or be published.

  • Cancel

Having problems with the form?

Contact Us Directly
  • Print

You can comment on most stories on You can also agree or disagree with other comments. All you need to do is be a Winnipeg Free Press print or e-edition subscriber to join the conversation and give your feedback.

You can comment on most stories on You can also agree or disagree with other comments. All you need to do is be a Winnipeg Free Press print or e-edition subscriber to join the conversation and give your feedback.

Have Your Say

New to commenting? Check out our Frequently Asked Questions.

Have Your Say

Comments are open to Winnipeg Free Press print or e-edition subscribers only. why?

Have Your Say

Comments are open to Winnipeg Free Press Subscribers only. why?

The Winnipeg Free Press does not necessarily endorse any of the views posted. By submitting your comment, you agree to our Terms and Conditions. These terms were revised effective April 16, 2010.


Make text: Larger | Smaller


Rumor's 30th Anniversary with Mike Wilmot, Darryl Lenox, Dave Hemstad & Derek Edwards

View more like this

Photo Store Gallery

  • A baby Red Panda in her area at the Zoo. International Red Panda Day is Saturday September 15th and the Assiniboine Park Zoo will be celebrating in a big way! The Zoo is home to three red pandas - Rufus, Rouge and their cub who was born on June 30 of this year. The female cub has yet to be named and the Assiniboine Park Zoo is asking the community to help. September 14, 2012  BORIS MINKEVICH / WINNIPEG FREE PRESS
  • A nesting goose sits on the roof of GoodLife Fitness at 143 Nature Way near Kenaston as the morning sun comes up Wednesday morning- See Bryksa’s Goose a Day Photo- Day 07- Web crop-May 09, 2012   (JOE BRYKSA / WINNIPEG FREE PRESS)

View More Gallery Photos


How would you vote on the Tories' upcoming non-confidence motion?

View Results

View Related Story

Ads by Google