Where Do You Get Your Information About Vaccine Safety?

Mar 22, 2013 | Updated May 22, 2013

Parents' worries about the safety of the human papilloma virus (HPV) vaccine are on the rise. And yet, doctors and scientists aren't more worried. What's going on?

In a study just published in the journal Pediatrics, researchers asked parents who didn't want to give their children the HPV vaccine why they were making that decision. In 2010, the biggest reason (17.4 percent) was that they didn't think it was necessary -- but coming in at a close second (16.4 percent) was concerns about its safety.

In 2008, only 4.5 percent gave safety concerns as a reason. So worry about the vaccine has nearly quadrupled.

You'd think that big an increase would happen because bad things happened with the vaccine, because there was an increase in the number of side effects, or because there was new information to suggest that the vaccine might not be safe. But that's not the case. If anything, experts feel more comfortable with its safety than before.

It's not like there aren't any possible side effects. Vaccines, like any other medical treatment, can have side effects. The vast majority of side effects of the HPV vaccine (like fainting) have not been serious. There have been a small number of more serious events that happened after the vaccine, including blood clots and even death. But the people who had the clots had other risk factors for getting clots, so it's not certain that the clots were caused by the vaccine. There hasn't been a common pattern to the deaths that would make it clear that the deaths were from the vaccine, but investigators are studying this carefully.

See, that's the problem. Just because X happens after Y doesn't mean that Y caused X. It may very well be that you got sick because the cream you put in your coffee was bad. But it might have been because the person standing next to you on the crowded train a few days before was sick. You had no way of knowing he was doing his best not to vomit on you as the jolts of the train bumped his face into yours. It's the same with vaccines -- knowing whether problems were actually caused by them can be tricky business.

Vaccines have to be rigorously tested before they can be given -- and their ongoing safety is monitored by the Centers for Disease Control and Prevention (CDC) and the Food and Drug Administration (FDA). There is a national database called the Vaccine Adverse Event Reporting System (VAERS) where reports of a health problem after a vaccine can be submitted by anyone, and the data is publicly available. But that's not the only way safety is monitored. There is also the Vaccine Safety Datalink, which is a partnership between the CDC and several managed care organizations, and the Clinical Immunization Safety Assessment Network (CISA), which is a partnership between the CDC and several academic medical centers.

When I write about vaccines, I often get comments from readers with stories about what happened to them or somebody they heard about. Or they quote the opinion or research of one particular person. These stories, opinions and research are important, of course -- but scientific research based on the experiences of thousands of people shouldn't be discounted.

I also get comments suggesting conspiracies, such as that the drug companies that make the vaccines are in cahoots with the CDC. Now, I'm no Pollyanna. I know that corruption exists. But that would have to be one doozy of a conspiracy. Thousands of people would have to work together in secret to make it happen. My experience of working with doctors and scientists is that they have strong opinions and don't like to be told what to do -- getting them to do the same thing is like herding cats. And for all of them to work together to knowingly cause harm... I simply can't imagine it. I also can't imagine that every single one of us who researches or gives vaccines is stupid, which is another argument I have heard from those who oppose vaccines.

I respect and support the right of each and every person to make the medical decisions they feel are best for themselves and their family. But as you make those decisions, it's really important to think carefully and clearly about where you are getting your information.

Vaccines can literally save lives. If you choose not to give one to your child, make sure that you have the best facts possible.