As outbreaks of preventable diseases such as whooping cough and measles increase in the United States, researchers from the Regenstrief Institute and Indiana University School of Medicine are investigating whether altruism, known to influence adults' decisions to immunize themselves, influences parental decisions to vaccinate their children.
"If enough people are immunized against a particular disease, it prevents outbreaks of that disease and protects the community. This is known as herd immunity, and it's a very important benefit of childhood immunization," said Regenstrief Institute affiliated scientist S. Maria Finnell, M.D., M.S., IU School of Medicine assistant professor of pediatrics. "But as we are seeing more vaccine-hesitant parents, we need to better understand the factors that influence parents' decisions to immunize their children so that pediatricians can effectively communicate to them the importance of the recommended shots."
As a first step in their investigation, the researchers, led by Dr. Finnell, conducted a systematic evidence-based analysis of peer-reviewed studies on parental decision-making regarding child immunization and found no study designed with the primary focus on "benefit to others" as a motivating factor. Their findings are reported in "The Role of Herd Immunity in Parents' Decision to Vaccinate Children: A Systematic Review," published in the September issue of Pediatrics, the official peer-reviewed journal of the American Academy of Pediatrics.
"Studies have shown that benefit to others is an effective motivator for adults to vaccinate themselves," said Regenstrief Institute investigator Stephen M. Downs, M.D., M.S., associate professor of pediatrics and director of Children's Health Services Research at the IU School of Medicine. "However, our review determined that it is not known whether the role of herd immunity—immunizing to benefit the community—plays a role in parents' decision regarding immunizing their children."
Now that they have reviewed the medical literature and found it inconclusive, Drs. Finnell and Downs and their co-investigators are completing a study to determine whether varying how immunization messages are framed influences vaccine-hesitant parents.