Every 1 point increase in effort tied to average 2 percentage point drop in annual coverage
'Foreign disinformation' social media campaigns are linked to falling vaccination rates, reveals an international time trends analysis, published in the online journal BMJ Global Health.
Every 1 point increase in effort is tied to an average 2% drop in annual coverage around the globe, and a 15% increase in the number of negative tweets about vaccination, shows the study, which forms part of a BMJ Collection on Democracy and Health published for the World Health Summit this weekend.
Last year, the World Health Organization (WHO) listed vaccine hesitancy--reluctance or refusal to be vaccinated because of safety concerns---as one of the top 10 threats to world health.
While vaccine hesitancy isn't new, the proliferation of 'anti-vaxx' messaging on social media is of particular public health concern, given that vaccination is seen as a key route out of the current coronavirus pandemic, say the researchers.
Deliberate 'disinformation' campaigns by foreign agencies on social media also have their part to play, they add.
To gauge the impact of social media use and foreign disinformation campaigns on vaccine hesitancy around the world, the researchers analysed two different dimensions of social media activity for up to 190 countries.
These were: the public use of Twitter to organise action/resistance; and the amount of tweets expressing negative sentiments about vaccines.
They also drew on national survey data about public attitudes to vaccination safety and annual vaccination rates for the 10 most commonly reported vaccine doses between 2008 and 2018.
They used recognised analytical tools to measure sentiment (Polyglot Python Library); public use of social media to organise (Digital Society Project or DSP); foreign sources of disinformation (Varieties of Democracy Institute expert network + DSP); public attitudes to vaccine safety (2019 Wellcome Global Monitor).
They also logged measures of GDP (gross domestic product) per head of the population for each country and levels of internet usage.
Analysis of all the data revealed that the prevalence of foreign disinformation activity was "highly statistically and substantively significant" in predicting a drop in average vaccination rates.
A one-point shift upwards in the five-point disinformation scale was associated with an average fall in the annual vaccination rate of 2 percentage points, and a cumulative drop of 12 percentage points across the decade.
