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Vaccine hesitancy and anti‐vaccination movements

2019; Wiley; Volume: 55; Issue: 11 Linguagem: Inglês

10.1111/jpc.14581

1440-1754

David Isaacs,

Zoonotic diseases and public health

In its 2019 New Year message, the World Health Organization (WHO) identified vaccine hesitancy, which they define as reluctance or refusal to vaccinate despite the availability of vaccines, as one of the top 10 greatest threats to global health.1 The others were air pollution, climate change, non-communicable diseases, pandemic influenza, fragile and vulnerable settings, antimicrobial resistance, high-threat pathogens such as Ebola, weak primary health care, dengue and HIV.1 The WHO described vaccination as one of the most cost-effective public health measures ever to combat disease. Vaccination currently prevents 2.3 million deaths a year, but could save a further 1.5 million lives annually with improved global vaccine coverage.2 I do have some sympathy with criticism that the term 'vaccine hesitancy' is used too broadly to include behaviours including active rejection of vaccines, when the word hesitancy really means a psychological state of uncertainty, not a behaviour.3 However, who are we to argue with the WHO? Worryingly, there has been a massive recent increase in measles cases globally, despite the availability of safe, highly effective vaccines for a virus that does not mutate significantly, has no animal reservoir and should be the third viral scourge of humanity to be eradicated following smallpox and polio.2 The reasons for current measles outbreaks are complex, vary from country to country and include pockets of low coverage from vaccine refusal in close-knit religious communities (United States), collapse of health systems (Venezuela), cross border importation, inadequate services and vaccine scare (Ukraine) and conflict (Yemen). They also include active rejection of vaccination. The measles vaccine-autism controversy2 is only part of the global story. In Europe, reported measles rose from 5273 cases (13 deaths) in 2016 to 25 869 cases (42 deaths) in 2017 and further to 83 540 cases (74 deaths) in 2018.4 Over 50 000 of the 2018 cases occurred in the Ukraine, where immunisation rates have plummeted to below 50%, and where parents reportedly will pay for fake vaccination certificates. In 2018, there were over 2000 measles cases in each of eight European countries including France, Greece, Israel and Italy. Australia eliminated endemic measles in 20144 and has maintained high population immunisation levels. The resultant herd immunity has prevented the few cases introduced by overseas travellers from spreading to the wider community. The role of the internet in fuelling vaccine hesitancy by spreading anti-vaccine propaganda is hotly debated.5 Vociferous anti-vaccination movements flood the internet with anti-vaccination messages. But the public has a healthy scepticism about relying on the internet for information about science, such as climate change deniers. Blocking anti-vaccine propaganda on the internet, as suggested by some, would threaten free speech. Anti-vaccination movements have existed for as long as vaccination. When Edward Jenner developed and popularised cowpox vaccination against smallpox in the late 18th and early 19th centuries, English satirist James Gillray famously depicted cows emerging from the bodies of terrified people being given cowpox vaccine (Fig. 1). After the English government unwisely addressed smallpox vaccine hesitancy in 1853 by introducing compulsory smallpox vaccination, 80 000 people marched through the streets of Leicester carrying banners opposing vaccination, a child's coffin and an effigy of Jenner.2 A WHO vaccine advisory group identified some of the key factors in vaccine hesitancy as complacency, inconvenient access to vaccines and lack of confidence.6 The advisory group emphasised the role of health workers, especially those in communities, in building public confidence.6 Trust is critical in maintaining public confidence in vaccines. What is paramount to creating this trust is strong interpersonal communication, not the provision of vaccine facts alone, which has relatively little impact on vaccine uptake.7 It seems most parents do not want to know more about vaccines, they want reassurance that they are safe. There is a wealth of research showing that the public trust health workers more than any other public officials. People take antibiotics although antibiotics sometimes cause adverse effects. The same should apply to vaccines. We must now focus our efforts on how we can strengthen vaccine communication between parents and health-care providers in an efficient and effective way, while being mindful of time constraints faced by busy clinicians. If doctors and nurses acknowledge that vaccines can rarely cause adverse effects, while confidently conveying the message that the benefits of vaccines far outweigh the risks, people are more likely to immunise their children.3 Hesitant health workers contribute to vaccine hesitancy. The family doctor and the paediatrician can instil interpersonal trust. Additionally, there is an important interplay between interpersonal and social trust, meaning trust in the government and in public health bodies. Such trust is earned by ensuring vaccines and immunisation programmes are safe and by open and honest communication with the public about vaccine safety.3 I thank Dr Margie Danchin, Associate Professor Hasantha Gunasekera, Dr Stephen Isaacs, Professor Julie Leask and Professor Mike South for comments on earlier versions of this manuscript.