H1N1 vaccine arrival refuels autism debate
The much-anticipated H1N1 vaccine has given new life to an ongoing debate about whether vaccinations in children can cause autism, a discussion that will likely heat up as Canada and other countries move closer to releasing the new vaccine.
From one side of the debate come assurances that vaccines are safe and there is no conclusive link to autism; from the other, warnings that there is a relationship and parents should think twice about giving shots to their children.
Canada's chief public health officer, Dr. David Butler-Jones, has repeatedly said that vaccines have a long history of being safe and effective. Weighing in on the autism debate, he noted in a recent interview with Canwest News Service that vaccines are given to children at around the same age as when neurological disorders can surface.
"You can have a close time frame," he said. "Just because something's associated in time does not mean it's causal."
Butler-Jones said he recognizes that parents are searching for answers about autism's cause, but added claims that vaccines are the culprit have not been proven.
"The studies have been pretty clear and consistent that vaccination is not the cause of many of the things that have been claimed around the vaccine," he said.
The benefits of immunization far outweigh the risks, said Butler-Jones, but he understands people need to think carefully about it.
"It's important that they get the facts — not the theory, not the conjecture, not the claims — but the actual facts about what we know about the vaccine and the disease and I think . . . virtually everybody would choose the vaccine," he said.
The theory that childhood vaccines are behind an upsurge of autism cases emerged in the 1990s and in recent years has gained high-profile advocates such as Hollywood star Jenny McCarthy, whose son was diagnosed with autism. McCarthy is among the people who believe children receive too many vaccines, too close together, and that a mercury-based preservative called thimerosal used in some vaccines is harmful.
McCarthy is passionate about her cause, but she has her critics who are equally fervent on the pro-vaccination side of the debate.
Harold Doherty, a New Brunswick parent who writes a blog about his son's experience with autism, says his opinion on the controversy lies somewhere in the middle.
"While I once accepted without questioning the public health authorities' position that there is no vaccine-autism connection, I am no longer so sure," he posted in one entry. In an interview, he told Canwest News Service that not enough research has been done for him to accept or reject the theory.
"I've never said that my son's autism was caused by vaccines, or that vaccines have been proven to be a factor. I do believe that the research has not been sufficient to rule it out," said Doherty.
There will be no end to the "vaccine-autism war" unless an observational study is done comparing autism rates between vaccinated and unvaccinated populations, according to Doherty, and the H1N1 immunization program that will get underway this fall is an opportunity for such a study, he said.
Thimerosal has been removed from most of the vaccines given to children, but it is contained in influenza shots, including the new H1N1 vaccine.
Public health officials have said the vaccine will be ready in early November and children age six months to five years are among those who should get it first.
The Public Health Agency of Canada's most recent statement on thimerosal, issued in 2007, concluded that the weight of evidence refutes any link between thimerosal and autism, but that the long-term goal of removing the preservative from vaccines is advisable as a way to reduce total environmental exposure to mercury.
Dr. Derrick MacFabe, an autism researcher based at the University of Western Ontario in London, said parents who believe their child developed an autistic disorder after being immunized must be heard.
"These people's stories about what's happened to their children are completely valid," he said. "You can't deny what these people are saying."
At the same time, people shouldn't have "tunnel vision" when it comes to pinning autism on a single cause, he said. Vaccines should continue to be studied, but so should a host of other factors, including environmental toxins and infectious agents, said MacFabe.