Most people wrongly believed that doctors and scientists are equally divided over the safety of the measles, mumps, and rubella (MMR) vaccine, according to new research carried out during the high profile public debate over the vaccine last year.
At the height of the media coverage the impression was created that medical scientists were split down the middle over the vaccine's safety, including reports of links with autism, say the study's authors, from Cardiff University.
Less than one in four people were aware that the bulk of the evidence favoured the vaccine, say the authors of the study. "Although almost all scientific experts rejected the claim of a link between MMR and autism, 53% of those [the people] surveyed at the height of the media coverage of the issues assumed that because both sides of the debate received equal media coverage, there must be equal evidence for each. Only 23% of the population were aware that the bulk of evidence favoured supporters of the vaccine," says the study.
The researchers looked at how three subjects—the MMR vaccine, genetics, and climate change—were reported by the media and at the public's knowledge of the issues.
The research was carried out between January and September 2002 and involved two national surveys of more than 1000 people and an analysis of 2214 newspaper, radio, and television stories. The study included 561 media reports on MMR over a seven month period. More than half these stories were concentrated in one month between 28 January and 28 February 2002.
The focus of the media reporting was the possible link between the MMR vaccine and autism, a link mentioned in more than two thirds of the articles, say the authors, Professor Ian Hargreaves, Professor Justin Lewis, and Ms Tammy Spears, who carried out the study with funding from the Economic and Social Research Council.
Almost half (48%) of the people surveyed believed that on public health issues the media should wait for confirmatory studies before reporting "alarming research," say the authors. But 34% believed that concerns about the MMR vaccine such as those of Dr Andrew Wakefield vaccine should be reported.
"The survey confirms that the news media play a key role in informing the way people understand issues such as the controversy around MMR. While [Dr] Wakefield's claims are of legitimate public interest, our report shows that research questioning the safety of something that is widely used should be approached with caution, both by scientists and journalists," said Professor Lewis.
"This is especially the case where any decline in confidence can have serious consequences for public health. The research also has implications for the debate about fairness in journalism, suggesting that legal definitions of impartiality in broadcast journalism should not be interpreted in a simplistic fashion."
Towards a Better Map: Science, the Public and the Media is available at the Economic and Social Research Council's website (www.esrc.ac.uk)