SciComm Corner – The SciComm crisis surrounding COVID-19 vaccines

Article written by Kelleigh Greene

Following the announcements of three approved COVID-19 vaccines, when many of us were dancing for joy, anti-vaccination – or ‘anti-vax’ – proponents around the world were ramping up their efforts. Twitter posts quickly began circulating drawing comparisons between the new COVID-19 vaccines and thalidomide – the notorious medication that led to thousands of children being born with congenital disorders in the 1960s. Conveniently, the posts failed to mention that the tragedies wrought by thalidomide led to strict new regulations for clinical trials that have ultimately helped medicine to reach the excellent safety records experienced today. Science, by its very nature, is a field that recognises and develops from past mistakes.

The rapidly developing global health crisis has put the scientific process on display for the world to see – for better or worse. Uncertainties and shifts in recommendations as new data becomes available – overlaid in some countries by confusing and convoluted messages from governments – have contributed to the collective anxiety surrounding COVID-19. Vocal anti-vaxxers have been swift to capitalise on the public’s unease.

The anti-vax movement is by no means a new phenomenon. However, COVID-19 represents the first truly global pandemic during an age of hyper-connectivity. Communities previously consisted of people sharing a geographical location. But now, groups with shared interests or beliefs assort themselves into online communities using social media, unhindered by the constraints of physical proximity. Between them, the social media giants – including Facebook, Twitter, Instagram, and YouTube – reach more than half of the world’s population.

Anti-vaxxers have used these tools to reach a larger audience than ever before. The Center for Countering Digital Hate (CCDH) recently published a report estimating that the 409 most popular English-language anti-vax accounts have 58 million followers. With many countries, such as the UK and the USA, in the midst of a resurgence in COVID-19 cases, it is becoming increasingly probable that vaccination is the only viable solution out of the public health crisis. The anti-vax movement threatens to undermine these efforts and has scientists across the globe worried.

Speaking to the Financial Times, the Director of the Vaccine Confidence Project Dr Heidi Larson said, ‘I hope that enough people take these vaccines, but I think it is going to be much more of a challenge than is recognised.’

Drowning in uncertainties

Vaccine refusal threatens to further complicate a crisis already shrouded in uncertainty. Achieving ‘herd immunity’ through vaccination – when so few susceptible hosts are available to the pathogen, preventing it from spreading – relies on enough people receiving a full course of vaccines. One problem scientists and officials face is that no one knows exactly what proportion of the population needs to be vaccinated for COVID-19 herd immunity to kick in.

The herd immunity threshold is largely dependent on the pathogen’s ability to spread through a population. The pathogen’s ‘R number’ gives an indication of how many susceptible people will be infected by a single contagious person. In measles, for example, the R number of 15 for a population with no immunity means that every contagious person spreads the disease to an average of 15 other people. We now know that the herd immunity threshold for measles is between 92 and 94%. But we have the benefit of hindsight. The threshold for COVID-19 could take years to be determined with any accuracy.

Scientists from The Chinese University of Hong Kong and the University of Leicester, UK, calculated wildly differing herd immunity thresholds for individual countries using the estimated transmission rate of the virus until March 2020. This ranged from 5.66% in Kuwait through to 85% in Bahrain. The World Health Organisation’s (WHO) best estimate for herd immunity is between 65 and 75% vaccination rate.

Behavioural strategies – such as social distancing – can help to reduce the transmission rate and therefore the herd immunity threshold. But as soon as those strategies are relaxed, the R number and herd immunity threshold jump back up again. New COVID-19 variants could also make adequate vaccination rates difficult to achieve, should they exhibit a higher transmission rate.

Additionally, local pockets of disease can occur – even when the theoretical level of herd immunity is achieved – where groups of susceptible people come into contact. The period of protection offered by the COVID-19 vaccines is currently unknown. If it is similar to the influenza vaccine protection – which fades after around four to six months – outbreaks among groups refusing to be vaccinated could reseed the virus to the wider population as vaccinated people become susceptible again.

Hospitals, emergency services, and funeral homes in countries struggling to gain control over COVID-19 are at breaking point. Of particular concern then is the number of front-line workers refusing vaccination. Reports from front-line industries in the USA suggest that the vaccination rate may be falling short of the WHO’s estimated herd immunity thresholds. Public Health Director of Riverside County in California, Kim Saruwatari, told the Los Angeles Times that about 50% of the county’s front-line workers had refused the vaccine, amidst California’s intensive care units overflowing with patients. Ohio Governor Mike DeWine reported that around 60% of nursing home staff had declined a vaccine.

Social media: SciComm’s nemesis

By examining data from 13 countries, researchers from the University of Liverpool, UK and Maynooth University, Ireland, revealed that as the pandemic has progressed the intention to vaccinate against COVID-19 has decreased, and the intention to refuse vaccination has increased. The CCDH’s report suggests that the shift in public sentiment may be a result of misinformation or the deliberate spreading of anti-vaccination propaganda. More than a third of people surveyed in November 2020 by King’s College London and Ipsos MORI said that they had seen or heard messaging encouraging COVID-19 vaccine refusal.

Much of this anti-vax messaging is reaching people through social media platforms. These tech giants – which rely on user-generated content – failed to acknowledge their platforms’ role in spreading misinformation and anti-vaccination rhetoric until a series of measles outbreaks in 2019. Even then their responses ranged from downranking or hiding content – by Facebook – or labelling it – by Twitter and YouTube. These measures were inadequate – since then, popular English-language anti-vax accounts have gained another 8 million followers, mainly in the USA, UK, Canada, and Australia.

The failure to remove misleading or anti-science content from their platforms has less to do with a moral objection to stifling free speech, or even incompetence. The CCDH suggests that the failure to act decisively comes down to profits. Anti-vax users net social media giants about $1 billion each year. Tolerance – and direct profiting off this content through paid adverts – has allowed anti-vax messaging to reach more people than ever before in these hyper-connected digital environments.

And while social media giants head to the bank, tax-funded healthcare systems foot the bill. CEO of the CCDH, Imran Ahmed, suggests that tech giants should contribute to the global effort to contain the virus by paying the billions accrued from the anti-vax movement back into healthcare systems.

In our modern digital age, tech giants will need to be held accountable for facilitating the spread of dangerous misinformation. As Imran Ahmed says, ‘Lies cost lives.’