Are we becoming immune to the vaccine message?

Much hope is being pinned to a vaccine as our route out of this Covid nightmare. But even if one is developed, would enough of the population be willing to take it? Amidst a growing movement of ‘vaccine scepticism’ online, there are signs that many people would take a lot of convincing to get themselves inoculated.

In New Zealand, one in ten people would refuse a Covid-19 vaccine. In Belgium, 30 per cent of people are either sceptical about a vaccine or would refuse one; and in the USA, fewer than half would get the jab. In a worldwide survey carried out by the World Economic Forum, 29 per cent of those who didn’t want a vaccine were not convinced it would work.

Here in the UK, the picture is much the same: a survey of 5,000 parents last month found that around 45 per cent would not have their child vaccinated against Covid-19, with many citing vaccine safety as the concern. Surveys don’t always give a full picture, of course, but they at least give a snapshot of the mood. And there are worrying signs that developing a Covid vaccine might not be enough in the fight against this disease.

The trend, rather than a snapshot, in how receptive people are to a vaccine is just as important. Professor Heidi Larson, at the London School of Hygiene and Tropical Medicine, observed that the number of people in the UK who are unwilling to take a Covid-19 vaccine has risen around three-fold from March to June this year. Prior to the pandemic, her separate research published this month showed that confidence in the UK for vaccines had actually been on the upward trend. So what is causing this rise in scepticism about a Covid vaccine?

The anti-vaccination movement – which has existed in some form since vaccines first began – can shoulder some of the responsibility. But the speed with which the likes of Google, YouTube, Facebook and Twitter are reacting to anti-vaccine messages means that their message is less likely to reach the general public.

What is more likely, and what professor Larson alluded to in a press conference, is that ‘People are constantly weighing up the imminent threat of the disease with the apparent risk of the vaccine’. This risk-benefit equilibrium underlines the basic principle to which a person consents to medical interventions. The threat of the virus was perceived to be at its highest at the beginning of the pandemic, when we witnessed the horrors unfolding in Wuhan and Lombardy and during the subsequent rise in hospital admissions and mortality witnessed here in the UK. Having worked in a busy hospital during the height of the pandemic, it is quite understandable that nobody wants to return to those days.

However, those days have passed and have been replaced by a new era that is baffling experts. Daily cases are rising exponentially, yet mortality remains very low; Sunday’s increase in daily cases of 3,330 corresponded with fewer than 10 new deaths. To put that into perspective, the first time the daily infection rate rose above 3000 on 1 April, 661 died with coronavirus.

As the vast majority of people who become infected with the virus survive and don’t require hospitalisation, then the perceived ‘imminent threat of the disease’ becomes less. It then becomes harder to convince people that a jab is worth it.

Another factor those who might refuse a vaccine point to is the safety risk. The vaccines we have today in the UK are generally safe. I must have had countless during my childhood and later as an adult due to my line of work and I would certainly recommend the current schedule. However, developing a new vaccine is a different game entirely and many drugs developed in history have failed to progress due to safety concerns.

AstraZeneca had to briefly pause their Covid-19 vaccine clinical trial due to an adverse reaction in a study participant. A preliminary report indicated that the adverse reaction was possibly an autoimmune neurological condition called transverse myelitis, although it has not been confirmed. The likely reason many jumped to this possibility, is that the condition has been associated with vaccines in the past.

Other immune reactions have been implicated in various vaccines such as Guillain-Barre syndrome associated with the Swine flu vaccine; respiratory reactions associated with the RSV vaccine trialled in homeless children in the 1960s; and haematological conditions such as immune thrombocytopenic purpura associated with the MMR vaccine.

These, along with other documented adverse reactions are why many vaccine companies have asked for indemnification in the countries that they are testing these Covid-19 vaccines in, so that they are not held financially accountable should patients suffer adverse reactions. Despite this, the public will be keenly following trial safety surveillance to weigh up the risk-benefit equilibrium.

However, the risk-benefit equilibrium goes beyond merely considering the ‘imminent threat’ and ‘vaccine safety’. It also includes the actual benefit derived from the vaccine. As yet, no vaccine has demonstrated a clinical benefit by preventing Covid-19 in humans despite promising laboratory results. Furthermore, a beneficial vaccine deemed to be clinically effective would have to stop infection in at least 50 per cent of those who receive it in order to attain herd immunity. Hopefully one of the many vaccines being investigated will achieve this. But without confirmation from trials, an already-sceptical public will take a lot of convincing.

What seems certain is that given the huge investment and political backing, a vaccine will undoubtedly appear for Covid-19. But whether it will be a magic bullet like the smallpox vaccine or whether it will join the long list of other failed initiatives like the HIV vaccine, remains to be seen. What’s more, even the development of a successful vaccine won’t be enough for some, who will refuse to take it. This is why alternative strategies need to be explored in parallel, and it isn’t enough for us to simply play for time while the hunt for a vaccine continues.