Extolling the safety of childhood vaccinations may only serve to strengthen the positions of those philosophically opposed to them

Extolling the safety and benefits of childhood vaccinations may only serve to strengthen and entrench the positions of those philosophically opposed to them, says new research led by University of Toronto scientists.

"Changing attitudes about pediatric vaccination can be challenging," says Dr. Kumanan Wilson, professor of medicine and health policy, management and evaluation at U of T, internal medicine physician at Toronto General Hospital, University Health Network, and lead author of the research. "Some parents have strongly held beliefs about the safety and benefits of vaccines and any attempts to try to change their minds may only strengthen their anti-vaccine sentiments."

Wilson and his colleagues from U of T and McMaster University sought to test the attitudes of people known to have views not supportive of vaccination. They randomly divided 97 participants into two study groups. One group received an evidence-based lecture on the benefits of polio vaccine while the other received a talk by a polio survivor. Participants completed surveys about their attitudes to vaccines before and after the presentations. "Before" surveys confirmed the researchers' initial hypothesis – these participants were generally non-supportive of vaccines with only nine per cent saying they would recommend the polio vaccine and six per cent saying they would recommend the MMR (measles, mumps and rubella) vaccine.

However, analysis of the "after" surveys revealed surprising results – some respondents reported being even more opposed to vaccination. After seeing the presentations, 25 per cent reported being less likely to recommend the polio vaccine and 38 per cent were less likely to think polio was a serious problem.

"For some parents, concerns about vaccines are deeply held and physicians need to be aware of these findings when confronting parents who are strongly opposed to vaccination," warns Wilson. "Prolonged discussions may be counterproductive and could in fact damage the physician-patient relationship." The study appeared the April issue of Vaccine.