Does the internet put people off vaccines?

Vaccinations for COVID have saved over 1.4 million lives in Europe alone, according to the World Health Organisation. Their rollout, however, was far from straightforward. Alongside logistical challenges, they were met with a wave of anti-vaccine misinformation that led to significant vaccine hesitancy across society, inevitably reducing their impact – at least to some extent. 

Like most fake news in the modern world, much of this misinformation was spread and consumed online. The internet, though, is also a useful tool for distributing positive, factual health information. In this sense, whether through social media advertising or through accurate news reporting, it was doubtless a key tool in encouraging COVID vaccine uptake across society.  

In the future, we are likely to face new disease outbreaks and pandemics, and vaccines will play a key role in how well we handle them and mitigate their impact. With that in mind, it’s vital we have a proper understanding of the net effect of online information on attitudes to vaccines – does the spread of internet information increase or decrease overall uptake? 

Measuring impact on vaccine uptake 

Gauging this is challenging. Previous research suggests online information has a positive impact on vaccine uptake rates, but this is difficult to prove. As internet access is pretty much ubiquitous in most developed economies, there is not a large enough group of internet non-users to compare against. 

To examine this further, our research looks back to the early 2000s, when home internet was still being rolled out. This allows us to explore the effects of online information by comparing the behaviour of those with access and those without, as well as the impact of socioeconomic factors such as deprivation and education levels. 

It’s vital we have a proper understanding of the net effect of online information on attitudes to vaccines

Specifically, we look at how online information affected uptake of the vaccine against measles, mumps and rubella (MMR) between 2000 and 2011 – the most rapid period of growth in internet access. A 1998 study, which was found to be false and later retracted, linked the MMR vaccine to autism in children, causing a decline in vaccine uptake and a general rise in vaccine hesitancy. 

But did the online spread of information, at least in part, facilitate this effect? To test this, we compared vaccination rates in children aged 0-1 and 0-5 against gradually rising internet access across our time range. The results show that internet access did decrease MMR vaccine uptake. Specifically, we found that a 25 per cent increase in internet penetration reduced vaccination rates in children aged 0-1 and 0-5 by 23.8 per cent and 19.1 per cent respectively. 

Demographic differences 

However, this effect is not consistent across society, as we know internet access is not random. In general, vaccination uptake is higher in less deprived areas with a higher proportion of high-skilled individuals. These areas also tended to gain internet access earlier, and we found that access to the internet is more likely to reduce vaccine uptake in these areas, compared with more deprived, less highly educated areas. 

The impact is significant: our results show that a 25 per cent increase in internet access in the most affluent areas in the UK caused a 22.4 per cent reduction in the vaccination rate for children aged 0-5. This is compared to an average decline across all areas of 19 per cent – in other words, the overall response to an increase in internet access in more affluent areas is approximately 3.4 per cent larger than the average. 

Societal effect 

This is consistent with what we know about people’s behaviour more broadly – that greater online access exposes them to great quantities of potentially misleading information, and that this information is more understandable to those who are more highly educated. Our findings also match what we know about attitudes to parenting, with wealthier parents tending to be the first to take action that they perceive to be protective of their children. 

Interestingly, however, there is evidence to suggest that internet access might have different effects in different countries. In Indonesia, for example, access to 3G broadband was found to have reduced COVID cases by approximately 45 per cent, with a more pronounced effect on those with higher education levels. While this is not specific to vaccine uptake (or the lack thereof), it highlights that the impact of online information is complex. 

The results show that internet access did decrease MMR vaccine uptake

The findings reported here are specific to the UK. They demonstrate that here, at least, increasing access to the internet has led to decreases in vaccination rates. Changing this state of affairs could be key to preparing society to better deal with future health crises.  

That means interventions from social media platforms, public health campaigns, and access to high-quality health information will be vital in getting a positive, factually accurate message out both quickly and widely. Combining these approaches, through policy and investment, will give us the best chance of overcoming health misinformation.

This article draws on findings from "Information and Vaccine Hesitancy: The Role of Broadband Internet" by Sofia Amaral-Garcia (Université Libre De Bruxelles), Mattia Nardotto (Université Libre De Bruxelles), Carol Propper (Imperial College London) and Tommaso Valletti (Imperial College London).