Largest global vaccine confidence survey reveals hesitancy hotspots

While vaccine confidence remains low in Europe, there are signs that public trust in vaccine safety has been increasing in some EU countries.

Of people surveyed in December 2019, those that ‘strongly agree’ vaccines are safe ranged from 19% in Lithuania to 66% in Finland.

The new study, including Imperial College London researchers, mapped global trends in vaccine confidence across 149 countries between 2015 and 2019, and is published today in The Lancet. It is based on data from over 284,000 adults (aged 18 years and older) surveyed about their views on whether vaccines are important, safe, and effective.

Our monitoring also helps us to understand which countries and social groups may be reluctant to take a COVID-19 vaccine. We are now in the process of collecting data for many countries across the world to understand confidence in a COVID-19 vaccine. Dr Alex de Figueiredo

The results show that within the EU, public trust in vaccine safety was increasing particularly in Finland, France, Italy, and Ireland – as well as in the UK. In the UK, confidence in vaccine safety rose from 47% in May 2018 to around 52% in Nov 2019.

In contrast, six countries (Azerbaijan, Afghanistan, Indonesia, Nigeria, Pakistan and Serbia) reported globally significant increases in the proportion of survey respondents strongly disagreeing vaccines are safe between 2015 and 2019, in what researchers describe as a "worrying trend”, with negative attitudes mirroring trends in political instability and religious extremism.

With hopes of a vaccine for COVID-19, authors say regularly assessing public attitudes and rapidly responding to any declines in confidence must be top priority to give the best chance to new life-saving vaccines.

Increasingly important global health issue

Public trust in immunisation is an increasingly important global health issue, with WHO declaring vaccine hesitancy as one of the top ten threats to global health in 2019. Declining confidence can result in vaccine delays or refusals, which is contributing to a rising number of vaccine-preventable disease outbreaks including measles, polio, and meningitis worldwide.

Co-lead author Dr Alex de Figueiredo, who conducted this research while at the Centre for Mathematics of Precision Healthcare in the Department of Mathematics at Imperial, said: “Regularly monitoring national attitudes to vaccines is important to establish baseline levels of confidence in vaccines across the world, allowing us to identify early warning signals of losses in confidence.

“Our monitoring also helps us to understand which countries and social groups may be reluctant to take a COVID-19 vaccine. We are now in the process of collecting data for many countries across the world to understand confidence in a COVID-19 vaccine. In the UK, we are surveying over 15,000 people to map these attitudes vaccines sub-nationally to identify local barriers to uptake.”

Professor Heidi Larson from the London School of Hygiene & Tropical Medicine, who led the research, said: “One of the main threats to the resilience of vaccination programmes globally is the rapid and global spread of misinformation. When there is a large drop in vaccination coverage, it is often because there's an unproven vaccine safety scare seeding doubt and distrust.

“There are also cases where vaccine debates have been purposefully polarised, exploiting the doubting public and system weaknesses for political purposes, while waning vaccine confidence in other places may be influenced by a general distrust in government and scientific elites.”

Global survey

In this study, researchers analysed data from 290 nationally representative surveys conducted between September 2015 and December 2019, combining previously published data from nearly 250,000 survey responses with 50,000 additional interviews from 2019.

Our findings suggest that people do not necessarily dismiss the importance of vaccinating their children even if they have doubts about how safe vaccines are. Dr Clarissa Simas

Modelling was used to estimate trends in public perceptions about the safety and effectiveness of vaccines, and the importance of vaccinating children. They also modelled the relationship between vaccine uptake in each country and demographics (age, sex, religious beliefs), socioeconomic factors (including income and education), and source of trust (such as family, friends and health professionals).

Across the European Union recent significant losses in confidence in vaccine safety were detected in Poland (a dip from 64% strongly agreeing vaccines are safe in Nov 2018 to 53% by Dec 2019), reflecting the growing impact of a highly organised local anti-vaccine movement.

Confidence losses

The analysis suggests that overall confidence in vaccines – including safety, effectiveness, and importance – fell in Indonesia, the Philippines, Pakistan, and South Korea between November 2015 and December 2019.

Risks of a dengue vaccine (Dengvaxia) in the Philippines in 2017 led to a dramatic drop in public confidence in vaccine safety and impacted the uptake of routine vaccines. In South Korea, however, online mobilisation efforts against childhood immunisation by communities such as ANAKI (Korean abbreviation of ‘raising children without medication’), have been identified as key barriers to vaccination.

Indonesia has witnessed one of the largest falls in public trust worldwide between 2015 and 2019, and the authors say negative attitudes may have been partly triggered by Muslim leaders questioning the safety of the measles, mumps, and rubella (MMR) vaccine, and issuing a fatwa (religious ruling) claiming that the vaccine was haram and contained ingredients derived from pigs, as well as local healers promoting natural alternatives to vaccines.

Importance of vaccines

The analysis suggests that confidence in the importance of vaccines (rather than in their safety or effectiveness) is most strongly linked with vaccine uptake. By December 2019, the majority of European countries were displaying increased levels of confidence in the importance of vaccination than in their safety and effectiveness.

“Our findings suggest that people do not necessarily dismiss the importance of vaccinating their children even if they have doubts about how safe vaccines are,” said co-lead author Dr Clarissa Simas from the London School of Hygiene & Tropical Medicine. “The public seem to generally understand the value of vaccines, but the scientific and public health community needs to do much better at building public trust in the safety of vaccination, particularly with the hope of a COVID-19 vaccine.”

In 2019, Iraq (95%), Liberia (93%), and Senegal (92%) had the highest proportion of respondents who strongly agreed that it is important for children to be vaccinated, while Hong Kong (36%), Russia (34%), and  Albania (26%) reported the lowest proportion strongly agreeing on the importance of vaccines.

The study also found that being male or less educated were linked with a lower chance of vaccine uptake, whilst trusting healthcare workers the most for medical or health advice, rather than family, friends, and other non-medical sources for health advice was associated with increased chances of vaccine uptake. Researchers found a weaker association between minority religious groups (or those refusing to provide their religious belief) and lower likelihood of vaccine uptake.

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‘Mapping global trends in vaccine confidence and investigating barriers to vaccine uptake: a large-scale retrospective temporal modelling study’ by Alexandre de Figueiredo, Clarissa Simas, Emilie Karafillakis, Pauline Paterson and Heidi J Larson is published in The Lancet.

Based on a press release by The Lancet.

All images by SELF Magazine.