London School of Hygiene & Tropical Medicine

A new global media surveillance system is identifying and systematically monitoring up-to-the-minute public concerns and rumours about vaccines originating from 144 countries.

The application could help public health officials respond more quickly and effectively to a loss of public confidence in vaccines before it results in vaccination refusals and disease outbreaks, according to an article published in The Lancet Infectious Diseases.

Lead author, Dr Heidi Larson from the London School of Hygiene & Tropical Medicine, said:  “Recent measles outbreaks in the UK, stemming from children not-vaccinated due to fears prompted by now-discredited research over a decade ago, is one example of the long-term consequences of broken public trust in vaccines.

“The Internet has speeded up the global spread of unchecked rumours and misinformation about vaccines and can seriously undermine public confidence, leading to low rates of vaccine uptake and even disease outbreaks.”

The new application builds on the capacity of HealthMap—an online surveillance resource that detects and maps early signs of disease outbreaks from electronic data sources such as news reports, blogs, social networking sites, and government announcements—to track the emergence and spread of public rumours and concerns about vaccines, vaccine programmes, and vaccine-preventable diseases from 144 countries.

Between May 2011 and April 2012, 10,380 reports were identified and categorised by location, disease and type of content—positive/neutral (69%) and negative (31%). The researchers also devised a typology of concerns to evaluate and prioritise reports according to their potential to disrupt vaccine uptake, to guide further investigation and intervention.

Of the negative reports, almost half were associated with vaccine impacts (e.g. vaccine suspension, refusals; 24%) and belief systems (e.g. religious beliefs, risk perceptions; 21%).

Dr Larson adds: “Real-time monitoring and analysis of vaccine concerns could help governments and public health officials locally, nationally, and globally understand where they should focus their attention and resources when a concern arises, and where specific vaccines might need more tailored engagement strategies.”

Find out more about the School’s Vaccine Confidence Project.

Publication

• Larson et al. Measuring vaccine confidence: analysis of data obtained by a media surveillance system used to analyse public concerns about vaccines. The Lancet Infectious Diseases. DOI: 10.1016/S1473-3099(13)70108-7