Friends and family may be key in parents' decisions on whether to vaccinate their young children, a small US study suggests. The study, of about 200 parents, found that those who had opted not to follow the standard vaccine schedule often sought advice from anti-vaccine friends and family.
Experts said it's not certain that the advice actually steered parents in an anti-vaccine direction: Parents who were already prone to shunning vaccines may have turned to like-minded people for reinforcement.
"It's the chicken-and-egg question," said researcher Emily Brunson, an assistant professor of anthropology at Texas State University, USA. "The answer is, we don't know which came first."
To be more sure, Brunson said, parents would have to be followed over time, to see whether undecided parents actually base vaccine decisions on advice from other people.
But Brunson said she thinks family, friends and others in parents' "social networks" really are an important influence.
Dr. Douglas Opel, of Seattle Children's Research Institute and the University of Washington, agreed.
"It is unclear how these groups influence parents. Do they simply reinforce the vaccine decisions parents would have made otherwise, or do they actually function as a way that provokes a parent to consider other ideas?" said Opel, who wrote an editorial published with the study, which appeared online April 15 and in the May print issue of the journal Pediatrics.