New IOM Report on Vaccine Risks: Will It Make Any Difference?

The Institute of Medicine has released a sweeping new report on the risks of eight common vaccines, noting that adverse effects are rare but exist - and knocking down, once again, the misconception that vaccines "cause" autism.

The question is, will the report, like so much research that came before it, make any difference in easing persistent public fears of childhood vaccines? Most of today's media coverage of the report suggested it won't.

The committee's carefully parsed language about how vaccines may or may not be linked to various side effects – "convincing evidence of a link," "inadequate evidence" to accept or reject a causal relationship" – isn't likely to comfort parents worried about the potential risks of vaccines for their young children. Anti-vaccine activists are likely to highlight many cases of serious health conditions in which the IOM committee said there was "insufficient evidence" to confirm or deny a link to vaccines.

Here's some background on the report:  federal health officials asked the IOM to examine adverse events associated with eight vaccines - varicella zoster, influenza (except 2009 H1N1), hepatitis B, HPV, MMR, hepatitis A, meningococcal, and those that contain tetanus - and to look at the evidence that those vaccines caused adverse events. The reason? To guide federal government decisions on how or whether to compensate people who say they were injured by vaccines.

A committee of experts did indeed find "convincing evidence" that some vaccines do cause serious adverse events, but they are rare and occur primarily in people with existing immune system disorders. For example, the live varicella zoster, or chicken pox vaccine, can in rare cases cause rather than prevent infection with the virus that causes chicken pox, leading to complications such as meningitis. The MMR (measles, mumps and rubella) vaccine also is convincingly linked to fever-related seizures in babies and young children.

But the report said the "evidence favors the rejection" of any link between the MMR vaccine and autism or type 1 diabetes.

Among the many stories covering the report, Gardiner Harris of the New York Times noted:

Many children injured by vaccination have an immune or metabolic problem that is simply made apparent by vaccines. "In some metabolically vulnerable children, receiving vaccines may be the largely nonspecific ‘last straw' that leads these children to reveal their underlying" problems, the report stated.

Carol Ostrom of the Seattle Times localized the report, writing that "Washington state, which has the highest rate in the nation of children who enter school without the required vaccines."

She also smartly noted what the committee's report did not answer, including how frequently vaccine-related side effects occur:

The committee also said it was not asked to answer the question ‘Are vaccines safe?' Nor did it have data to address the concern by many parents about multiple vaccines given at one time.

Ironically, a quick search of headlines about the report reveals a lot of "vaccines are generally safe" wording.

Here are some resources for reporting on vaccines in your community:

Covering Vaccines: Science, policy and politics in the minefield – Journalist Amy Wallace offers advice on covering vaccine safety and navigating anti-vaccine politics.

Useful Resources for Reporting on Vaccines: This guide offers reputable online resources for reporting on vaccine safety, effectiveness, politics and legal issues.

CDC Vaccination Coverage and Surveillance Page: Provides national statistics and information about vaccination rates for children and adults.