Coronavirus (COVID-19) vaccine barriers and incentives to uptake: literature review

Executive summary

Introduction

Vaccines are considered to be the best weapon in defeating Covid-19, given their ability to reduce risk of infection, hospitalisation and death. Launched in December 2020, the Covid-19 vaccination rollout has represented the largest mass immunisation programme both in British and Scottish history.

Despite recording some of the highest percentages of vaccinated people in the world, the UK saw vaccination rates levelling off at the end of 2021. This literature review will explore the reasons for changes in uptake and how they relate to particular groups in society.

Covid-19 vaccine uptake in Scotland

Scotland presents significant differences in uptake, with minority ethnic groups, those living in the most deprived SIMD deciles, younger people, men and pregnant women more likely to be hesitant.

Objectives and research questions

The analysis of the sources presented in this literature review suggests answers to the following research questions:

• How does knowledge and understanding of Covid-19 affect vaccine uptake?
• What are the practical and physical barriers to uptake encountered by the eligible population?
• To what extent do concerns about vaccine safety cause people to disengage from the programme?
• What is the role played in vaccine uptake by broader beliefs and attitudes?
• What lessons can be learned that may help to engage lower uptake groups better?

Methods

A standard literature review was undertaken between November 2021 and February 2022 on a number of search engines, such as KandE (a Scottish Government resource covering several databases), Google Scholar, PubMed and ScienceDirect. The body of evidence consists of 106 papers.

Terminology

This review makes reference to the term "vaccine hesitancy" as defined by the World Health Organisation Strategic Advisory Group of Experts (WHO SAGE), namely the "delay in acceptance or refusal of vaccination despite the availability of vaccination services". It also uses the WHO SAGE "3Cs model" – complacency, convenience and confidence – as a reference to report key findings on barriers and possible incentives to uptake.

Key findings

Vaccine hesitancy affects uptake of a number of routine vaccinations in the UK. Yet, Covid-19 vaccines present a degree of uniqueness due to the speed at which they have been developed and the intense efforts that have been put to their promotion. The sections below explore how vaccine hesitancy varies by context and is influenced by a number of factors.

Complacency

Complacency results from a consideration of vaccines as unnecessary due to one's perception of being at low risk of catching Covid-19 or experiencing severe disease outcomes.

The underestimation of the consequences deriving from infection relates both to lack of knowledge or misconceptions about Covid-19, and to the absence in one's social network of people who have become severely ill with the virus. Research shows that the belief that vaccination can be avoided by relying on one's immune system or on the diligent adoption of protective measures is also common.

Levels of complacency have varied over time and have been influenced not only by personal and social factors, but by the number of cases, emerging science and gradual immunisation due to the vaccines or natural exposure to the virus.

Suggested solutions to address misconceptions and increase awareness of risk include the use of public health information highlighting how hesitancy can cause further outbreaks and deaths, and communication campaigns targeting public perceptions about the risks associated with Covid-19.

Convenience

Convenience pertains to vaccine accessibility, not only in physical terms (e.g. access to vaccination clinics), but also in relation to actual availability of doses (including different kinds of vaccines) and ability to understand information and/or engage with digital booking systems.

Accessibility barriers can be very practical, such as inconvenience of appointments, or access to and costs of public/private transport. However, social or psychological barriers also play a role (e.g. anxiety caused by unfamiliar surroundings and people). Lack of or limited access to health care (e.g. due to residential segregation or lack of understanding of the functioning of the medical system) can also represent an obstacle to vaccine uptake and act as a cause for increasing inequalities.

Recommendations to overcome these barriers include: use of workplaces, community centres, places of worship, and pharmacies for vaccination, as a way to target those individuals who are not registered with primary care services or may be impacted financially if they have to take time off work or pay for travel to vaccination sites; service provision in multiple languages and through multiple channels (e.g. emails, letters, text messages, posters, social media, etc.); proactive engagement and co-production of messaging with relevant communities.

Confidence

Confidence relates to the issue of trust, both in vaccine effectiveness and safety, and in the political and medical professionals and systems that deliver it.

Trust in vaccine safety/effectiveness

The issue of trust in Covid-19 vaccines originates from worries about their side effects (including long-term side effects), their lack of effectiveness (due to the emergence of new variants), and the thoroughness of research trials and quality standards in vaccine production (given the unparalleled speed at which vaccines have been developed).

Emerging science and changing guidance have impacted uptake and willingness to get vaccinated through the confusion they have generated in the public who has been exposed to an overabundance of information on the clinical characteristics and efficacy of multiple vaccines, immune response, duration of immunity and need for further doses. This confusion has been aggravated by the circulation of false information on social media, which has become the preferred platform for the anti-vaxx movement.

In the literature, recommendations to improve confidence in vaccine safety and effectiveness include: promotion of a direct and two-way dialogue with different groups and communities in order to meet specific needs; educational campaigns and initiatives restating that the benefits of getting vaccinated outweigh the risks of catching the virus, also aiming to inform the public about the rarity of some side effects and target misinformation; greater control exerted by social media companies on the content shared on their platforms; further research into reported side effects such as menstrual changes after vaccination to help dispel fears related to fertility; and a focus on the role that medical professionals can play as providers of information about clinical trials and the regulatory process, but also about their own experience of vaccination.

Trust in the political and medical system

Hesitancy has also been linked to lack of trust in the system that delivers the vaccines. This system extends from government institutions and health care providers to the scientific community and Big Pharma. Distrust in the companies that produce the vaccines and the agencies overseeing their development has often been fed by conspiracy theories on falsification or concealment of data for financial gain or political objectives.

The issue of trust is strongly correlated to ethnicity in the studies presented in this review. Concerns about certain minority ethnic groups being used to test the vaccines or being harmed on purpose through them, and the association of Covid-19 vaccines with infertility and alleged population planning, are common themes. These can be linked to a history of unethical research and experimentation, underrepresentation in clinical trials, cultural and structural racism, and systematic discrimination.

Possible solutions to improve uptake suggested in the literature include: collaboration with third sector organisations and development of community networks; community education carried out by healthcare professionals belonging to ethnic minorities; administration of vaccines in the presence of trusted family physicians; training for health care professionals in culturally tailored conversations; and use of online platforms to spread trustworthy vaccine information.

The choice of who promotes public health messaging has been deemed crucial, with the following recommendations: recourse to expert scientists, rather than politicians, to address vaccine questions and concerns; involvement of faith leaders, as decisions on whether to have vaccines are also determined by beliefs about religious acceptability; and use of Community Champions as trusted voices capable of promoting initiatives in a way that is responsive to specific local challenges.