Delaying first shot lessens risk, U of M researcher’s study shows
(Article retrieved from article in Winnipeg Free Press)
Fri Jan 25 2008
By Jen Skerritt and Alexandra Paul
Researcher Kozyrskyj found nearly 14 per cent of the children who received their first shot of the diphtheria, pertussis and tetanus vaccine at two months of age developed asthma — compared to only 5.9 per cent of children who were vaccinated more than four months after the scheduled date.
Manitoba recommends vaccinating children at two months, four months, six months and 18 months of age.
CHILDREN who have their first routine vaccination delayed by more than four months cut their risk of asthma in half, a University of Manitoba researcher has found.
Anita Kozyrskyj, an asthma researcher in the U of M faculty of pharmacy, studied the immunization and health records of 14,000 children born in Manitoba in 1995.
The vaccine can cause an allergic reaction and Kozyrskyj said researchers are speculating whether children’s immune systems are better able to handle the vaccine’s side-effects when they’re older. The pertussis vaccine used in Manitoba before 1997 caused fever in some children, and some studies have linked fever in early childhood to a greater risk of developing asthma.
The study’s findings are going to be published in the U.S. Journal of Allergy and Clinical Immunology within the next few weeks.
“We’re thinking that maybe if you delay this allergic response until a bit later, the child’s immune system is more developed and maybe you’re not seeing this effect,” Kozyrskyj said.
The findings come as little surprise to parents who have spoken out against the risks of vaccinating infants at an early age.
The prevalence of childhood disorders like asthma and auto-immune disorders like autism has increased over the last few decades, leaving many parents wondering whether childhood vaccinations may be contributing to the rise.
“They’re barely out of the protection of the womb before we’re sticking vaccines in them,” said Irene Gergus, a Winnipeg mother whose son Andrew lost his ability to speak shortly after receiving his fourth DPT shot at 18 months in 1993.
“I’m not against vaccination. I just think they’re too young to be receiving (them).”
One parent said she feels vindicated for holding off on vaccines for her two-year-old son.
“I’d done significant reading, and the one thing I’d read is that children are not born with a fully developed immune system and there is this idea that perhaps you should wait for the immune system to mature before you start messing with it,” Amanda Jeninga said.
Little Dylan Jeninga will be two in two weeks and his mother said she and her husband will consider vaccines again then.
Eight months ago, Jeninga said she had a run-in with a doctor “who tried to scare me into giving (Dylan) his vaccination.” She held out. “I made a good decision,” she said.
Another parent said his son had his shots as a baby and then at age three developed asthma. Trevor, now a man in his 20s, still suffers from asthma as an adult. Ron Hodgkins said he and his wife will never know for sure if vaccines played a role in their son’s chronic breathing problems, but it makes him wonder.
“Had we known way back when, then it would have been a different story,” Hodgkins said. “I would have questioned it,” he said about giving vaccines to babies.
Kozyrskyj is the first researcher to study the connection between asthma and vaccines, but said she does not believe the findings will spur a change in the province’s vaccination schedule. She said Japan recommended children under 10 months not be vaccinated between 1975 and 1988, and the country saw a spike in the number of childhood cases of whooping cough.
Kozyrskyj said she is “pro-vaccination” and noted the safety and effectiveness of vaccines has been studied for years.
“It’s not an alarm bell,” she said. “We have many years of research on these vaccines and I would say the benefits, by far, outweigh the risks.”
Of the 14,000 immunization records Kozyrskyj studied, 11,531 children received at least four doses of DPT.
Overall, nearly 12 per cent of the children who received at least four doses of DPT had asthma. The majority of children who had asthma lived in urban areas and were predominantly male.
Kozyrskyj said researchers did not study the risk of asthma among children who did not receive any vaccinations, saying only about 100 children in the province did not receive DPT — a number that would not be statistically significant.
What is asthma?
* Doctors define asthma as a chronic inflammatory disease of the airways in the lungs.
* The symptoms are: shortness of breath, tightness in the chest, coughing and wheezing.
Asthma is the leading cause of hospital stays for children under age 15.
* Asthma is the leading cause of absenteeism from school in Canada and the third-leading cause of missing work.
Asthma rates are rising in Canada and around the world, especially over the last 20 years, but doctors still don’t know why. There are a number of theories, including cleaner living environments, processed foods and stress.
In 2000, the Manitoba Law Reform Commission released a report that urged the province to compensate children hurt by vaccines.
The report said Manitoba’s current compensation scheme is inadequate, and recommended a no-fault scheme similar to what’s in place for car accidents and workers injured on the job.
At the time the report was released, two cases of children damaged by vaccines were before the Manitoba courts. One case claimed the child suffered brain damage.
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