Falling coverage of life saving vaccines secondary to doubts over vaccine safety has contributed to outbreaks of measles in Europe in the past year, and other infectious diseases could follow. It is known that while social media platforms provide outlets for the dissemination of factual information supporting vaccination, they equally allow the spread of misinformation. Previously remote sources of misleading information can now reach a global audience. The approach of many from the public health sector has largely centred on issuing reliable scientific evidence and pro-vaccination messages. However, researchers in the field of applied computer sciences have advised that more attention needs to be paid to the sources of disinformation.
In a recent paper, Broniatowski and colleagues reported on sophisticated techniques used by Twitter trolls, “individuals who mispresent their identities with the intention of promoting discord”, known to be linked to the Russian government funded Internet Research Agency. They utilised a database, published by NBC News, of troll accounts that were purged by Twitter following investigations in the wake of the 2016 US presidential election. The Russia-linked trolls had frequently used the hashtag #VaccinateUS. The researchers found that tweets with this hashtag in fact carried equally pro- and anti-vaccination sentiments, and often sought to provoke debate concerning vaccines, in an attempt to throw the scientific consensus into doubt. Their arguments were often tied to appeals to “freedom”, “democracy” and “constitutional rights”, and conspiracy theories focusing almost exclusively on the US government. By contrast, other vaccine-related tweets focused more on arguments concerning parental choice, and conspiracy theories suspected a wide variety of culprits.
Broniatowski and colleagues considered that the vaccine debate has been “weaponized”. Yet this is not only a political weapon, but one whose casualties can be counted in vaccine-preventable deaths. Therefore public health authorities must leverage computer science methods to identify the sources of malicious social media content and, if possible, work with social media platforms to remove accounts with false identities and bots with automated production of anti-vaccine content.
Anti-vaccine messages are not only spread by secretive government agents, however. Even medical doctors have been chief in leading anti-vaccine opinion. Of course, a well-known study in 1998 by the British doctor Andrew Wakefield, which has now been retracted and discredited, has been a source of challenges to vaccine confidence. And this was not a fringe, outsider research project; it was conducted at one of the UK’s leading teaching hospitals and published in the high-impact medical journal, The Lancet. Although now barred from practising medicine in the UK, Wakefield has found ample space for his anti-vaccine sentiments in the US, even meeting with Donald Trump in 2016 to discuss the subject. Furthermore, his anti-vaccine outreach activity has been linked poor vaccination coverage and an outbreak of measles among a community of Somali origin in Minnesota.
When such distrust finds a foothold it can spread rapidly in society. For example, the recent outbreak of measles in Ukraine, with over 34,000 cases in the last 12 months, has been related to a lack of vaccine confidence among doctors. Anxieties over vaccination increased subsequent to the death of a 17-year-old boy during a vaccination campaign in 2008. The law in Ukraine deems the vaccine to blame if a child dies within 30 days of vaccination, and the health professional administering the vaccine can be suspended from practice pending further investigation. In that case, both the doctor involved and the deputy Minister of Health were prosecuted, and the vaccination campaign was suspended. However, investigations found no evidence that vaccination caused the boy’s death, and some have suggested that the punitive actions were politically motivated. This led to serious hesitancy amongst doctors, fearing similar litigation. In the face of the measles epidemic, the World Health Organization (WHO) has campaigned to re-establish vaccination coverage in Ukraine.
To maintain trust in vaccines, policies regulating health care professionals should avoid creating legal hazards to their engagement with vaccination programmes. Health care professionals must be better informed and equipped by public health authorities to educate parents on the benefits of vaccination. Researchers and authorities must improve engagement with the public and increase transparency in their practices. The WHO recommends, however, that professionals avoid trying to correct false claims, as repeating them can counter-productively provoke controversy around vaccines. Thus, engaging directly with anti-vaccine arguments on social media- which often disregard scientific reasoning and can be politically loaded- may only act to feed the trolls.