SUNDAY, SEPTEMBER 25, 2016

Social norms influence vaccination decisions, disease spread

The response to societal pressures about vaccination directly impacts the spread of pediatric infectious diseases in areas where vaccination isn't mandatory, according to a recently published study in Proceedings of the Royal Society B.

Canadian researchers at the University of Guelph and the University of Waterloo determined they could forecast the observed patterns of population behavior and disease spread when anti-vaccine sentiment is strong.

"If vaccination is not mandatory and disease is rare, then a few parents will be tempted to stop vaccinating their children," Chris Bauch, one of the study authors, said. "More parents adopt this behavior as social norms begin to change and it becomes increasingly acceptable to avoid some vaccines. Obviously, when enough parents are no longer vaccinating, the disease will come back."

While pediatric vaccination is mandatory for most children enrolled in public education in North America, the number of parents applying for vaccinations is increasing. Bauch said that as the trend continues, Canadians may once again become susceptible to vaccine-preventable diseases.

"Parents are not cold, clinical rationalists who base their decisions only on data," Bauch said. "They are strongly influenced by other parents and what they read. Our research suggests that health officials need to have a really good understanding of the social context to better understand vaccine scares and why people refuse vaccines."

Bauch suggested that health officials use predictive modeling to plan for responses to vaccine programs. He said the researchers would continue to study how social norms interact with disease spread. The research may result in an index that would help determine which populations are more susceptible to vaccine scares and prevent them from happening.