Negative messages about children’s vaccines are more likely to be spread on Twitter than positive messages, according to research led by Marcel Salathé, an assistant professor of biology at Penn State University.
In order to assess the nature of vaccine sentiments on Twitter, the researchers began by tracking the vaccine-related tweets to which Twitter users were exposed, specifically related to the 2009 H1N1 (“Swine flu”) vaccine. They then analyzed the tweets using a computer algorithm, and categorized them as positive, negative or neutral. A statistical model was developed to take into account the number of individuals each Twitter user was following, whether those individuals tended to tweet positive or negative messages related to the vaccine and how many positive and negative tweets each of those individuals sent out.
The main finding was that negative opinions regarding vaccines were spread much more easily than positive opinions. Researchers also reported that a tweeter who had connections with users expressing positive sentiments was not encouraged to tweet more positive messages, but those with connections to tweeters sending negative messages were more likely to tweet more negative sentiments. And the last finding, the most “bizarre” and “discouraging” according to researchers, was that even a “high volume of positive tweets seemed to encourage people to tweet more negatively…Pro-vaccine messages seemed to backfire when enough of them were received.”
Researchers hope that if further studies can shed light on why positive messages receive a negative response, public health officials “could use that information to send positive messages in a way that would be more likely to have the intended effect.”
ACSH’s Dr. Gilbert Ross notes, “This is a really important problem we in public health communication need to confront, from a scientific and medical point of view: trying, with apparent lack of success, to counter such baseless fear of vaccines. There’s absolutely no evidence that they’re harmful, and yet this mythology about the dangers of vaccines that really accelerated thanks to Andrew Wakefield’s fraudulent study in 1998 seems to have taken root among a fairly widespread segment of the population, with 30 percent of parents in some areas suspecting vaccines and delaying vaccinations of their children. This exposes not only their own kids, but their classmates and their families to potentially dangerous childhood diseases.”
One New York mom says she did plenty of research before vaccinating her youngest son, but says she’s not surprised with the study’s outcome. “It’s something different, so they’re drawn to something different,” Braete Newman says. ”The negative- even in the news, seems to draw people’s attention more than the positive.”