In the 1960s, academics studying rumours drew inspiration from epidemiology. They noted how such stories spread through communities, “infecting” some individuals while others seemed immune, and how more resistant populations could stop their spread.
Their insights have in turn been taken up by health professionals. Hearsay can be useful, helping to catch disease outbreaks. It can also be deadly. Though vaccine hesitancy is as old as vaccines themselves, it has risen sharply in many countries in recent years. Unfounded scare stories about the safety of immunisation programmes have contributed to growing scepticism and outright refusal, with fatal consequences. In her new book Stuck: How Vaccine Rumours Start – and Why They Don’t Go Away, Prof Heidi Larson notes the paradox: we have better vaccine science, more safety regulations and processes than ever before, yet a doubting public.
For the foreseeable future, demand for Covid-19 vaccines is likely to far outstrip supply. The US biotech firm Moderna has now joined Pfizer/BioNTech in announcing a vaccine with more than 90% efficacy in protecting people from Covid-19, but it will not be available outside the US until next year. The Oxford University/AstraZeneca candidate is some way further off in its work.
But while many are thrilled by the prospect of immunisation – three in four adults globally have said they would take it up if it were available – the unusual speed with which these products have been developed and tested has prompted anxiety among others, including those normally sanguine about vaccines. While 72% of Americans said in May that they would definitely or probably get a vaccine, that had dropped to 51% by October.
Fearmongering has played a part, with some of those responsible profiting politically or financially. Social media has produced an “infodemic”, allowing unfounded claims to spread internationally in hours or days – with algorithms pointing people toward more extreme content. Undoing the damage caused by anti-vaccination campaigns can take years or decades. Though internet companies are belatedly taking some action, more needs to be done.
Yet the problem is not merely disinformation, but why it is believed. Prof Larson, who runs the Vaccine Confidence Project at the London School of Hygiene and Tropical Medicine, warns that simply dismissing rumours can entrench them. When people’s questions or concerns are batted away, and they feel they are being treated as stupid, doubts can grow and vaccine ambivalence turn to scepticism and outright refusal.
Effective challenges to anti-vaccination messages must come before this hardening of attitudes occurs. It can feel baffling and frustrating when well-tested evidence fails to counter wild assertions and unverified anecdotes, but there is some underlying logic to suspicions. It is true that big pharma is often short on scruples; that governments don’t always make the right decisions about people’s lives; that medical staff can be dismissive of valid concerns; and indeed that vaccines are not entirely without risk.
In the US, where there is a horrific history of white scientists experimenting on black people without their consent, and ongoing racial discrimination in healthcare, African Americans are much less likely than whites to say they would take a Covid-19 vaccine, despite being twice as likely to die from the illness. Good communication about the new vaccines will mean not only clarity about the advantages and safeguards, but acknowledgments and explanations of potential risks and uncertainties, putting them into context.
Prof Larson argues that anti-vaccine sentiment flourishes when people do not feel a sense of dignity or control over their own lives. The last year has exacerbated such emotions, and they will not disappear when lockdowns end. Restoring confidence in immunisation may, in the long run, require the much more fundamental rethink that many hoped this pandemic might produce: a reappraisal of who and what is valued, and how we should be living and relating to each other.