A Rapid Systematic Review of Public Responses to Health Messages Encouraging Vaccination against Infectious Diseases in a Pandemic or Epidemic

"Determining the success of previous health campaigns relating to pandemics and epidemics can inform future communication strategies for promoting vaccine uptake."

Even if people's expressed willingness to get a vaccine SARS-CoV-2, as gauged in global surveys, translates perfectly into vaccine uptake, it is still likely that vaccine hesitancy will impact the vaccination effort against SARS-CoV-2. The aim of this review was to identify and synthesise evidence relating to effective messaging for encouraging vaccination in order to prevent virus transmission during pandemics or epidemics, including COVID-19. In light of evidence of the promise that involving key stakeholders in the design of public health messaging holds (e.g., by fostering co-creation of materials with the understanding of those we wish to engage in target behaviours), the review also examines patient and public involvement (PPI).

A rapid systematic review was performed by searching PsycINFO, MEDLINE, healthevidence.org, OSF Preprints and PsyArXiv Preprints in May 2020 for studies including at least one health message promoting vaccine uptake of airborne-, droplet-, and fomite-spread viruses. Included studies were assessed for quality using the Mixed Methods Appraisal Tool (MMAT) or the Assessment of Multiple Systematic Reviews (AMSTAR), and for PPI in the research. Ultimately, 35 articles - most of which reported messages for seasonal influenza or H1N1 - were included in the review. Characteristics of the articles included in the review and the types of intervention evaluated are presented in Supplementary Table S2 in the paper. Messages included emails, letters, leaflets, text messages, websites, television broadcasts, newspaper articles, and mass media campaigns.

Synthesis of results:

• Evidence of impact of messaging on behaviour: 8 of the 35 studies described successful vaccine promotion campaigns for increasing uptake. These included community- or hospital-wide mixed media messages, text message prompts sent from local physician clinics to adults from high-risk groups, text prompts with information about virus prevention and addressing misunderstandings about vaccination, the inclusion of a map with vaccination clinic locations in an email, and efforts to ensure messages were credible, clear, and provided honest information. Studies showing no impact of messages on vaccination uptake included leaflets providing information about influenza and the benefits of vaccination, a text message reminder prompt from a local practice, and an educational TV campaign encouraging a range of preventative behaviours including vaccination.
• Evidence of impact of messaging on behavioural influences:
  • 11 studies described successful vaccine promotion messages for improving either intentions or willingness, including framing losses when the message was collectivist, and, framing gains by emphasising benefits to society, using formal (rather than colloquial) language and shorter messages, including information about virus susceptibility and severity and benefits of vaccination, presenting risks in a socially and personally relevant way, fostering media multitasking while viewing health websites, and presenting messages on white backgrounds with red text. Interventions showing no impact of messages on intentions or willingness included using personal stories in messages and messages including basic risk information alone. Emphasising uncertainty in messages had a negative impact on willingness to be vaccinated in a hypothetical influenza scenario.
  • 15 of the final 35 studies reported the attitudes and beliefs of the general public or specific population groups towards vaccination. Messages improving attitudes towards vaccination included loss framed messages with collectivist appeals when presented as text (rather than images), and gain framed messages including images. Successful messages for improving perceived effectiveness or benefits of vaccines emphasised reduction in risks and used relative risk framing. Leaflets that were personally relevant and emphasised susceptibility and severity of viruses and the benefits of vaccination increased beliefs about capability to get vaccinated, as did narrative messages including personal accounts of people who took up a vaccine. Campaigns that influenced negative beliefs about vaccination included messages not providing honest safety information about vaccines, using "fear appeals" and over-emphasising the dangers of viruses, and emphasising uncertainty. Three studies reported that providing official information sources, emphasising the safety and effectiveness of vaccines, and providing basic information about the risk of vaccines were also found to have a negative impact on beliefs about vaccine effectiveness.
• Evidence on information needs: 12 of the 35 studies reported acceptability to the general public or specific population groups of messages and/or on levels of knowledge or understanding of the information shared in messages. Messages found acceptable by audiences include factual, risk-reducing messages, narrative messages, gain-framed messages, and loss-framed messages. Less acceptable messages included health-enhancing messages and those eliciting anticipated regret. Information needs highlighted by studies included gaps in understanding of how long it takes to build immunity following vaccination, whether vaccines for one virus can offer protection against another, and unfamiliarity with vaccine-related terminology. When health information was presented through narratives whereby the intended population was the centre of the story, these messages were better understood than didactic messages that aimed to instruct.
• PPI: 2 of 35 articles described the involvement of patients or the public in the research process (e.g., in the intervention design, in the steering group). No studies involved patient or public involvement groups in the analysis or interpretation of their findings.

This review also identified concern among populations about the risks of vaccines prompted by messages, which impacted on beliefs about vaccine effectiveness, such as concerns about side effects, vaccine safety, and the speed vaccines have been developed to manage global pandemics. A systematic review of studies from the H1N1 pandemic found that reporting the threat of a virus honestly and presenting both known and unknown factors can improve the population's perceptions and trust during times of public health crisis. This finding is consistent with research specific to SARS-CoV-2 that found that individuals reporting higher levels of trust in information from government sources were more likely to accept a new vaccine for SARS-CoV-2.

In short, evidence from moderate- to high-quality studies for improving vaccine uptake included providing information about virus risks and vaccination safety, as well as addressing vaccine misunderstandings, offering vaccination reminders, including vaccination clinic details, and delivering mixed media campaigns across hospitals or communities. Behavioural influences (beliefs and intentions) were improved when: shorter, risk-reducing or relative risk framing messages were used; the benefits of vaccination to society were emphasised; and beliefs about capability and concerns among intended populations (e.g., vaccine safety) were addressed. Clear, credible, messages in a language intended groups can understand were associated with higher acceptability. This can be achieved by co-designing messages alongside the communities teams are hoping to reach with messages. Furthermore, consulting groups at higher risk of contracting viruses when developing messages can help ensure campaigns are sensitive to their needs and are not perceived to be discriminatory.

In conclusion: "Messages could be improved by ensuring they address the information needs of target populations, use credible sources, are personally relevant, shorter, and are honest about what is known about vaccines without over-emphasising the health benefits of vaccination. Vaccine eligibility should be clear, which may involve tailoring messages as new information becomes available. Health authorities designing campaigns should review the delivery preferences of target populations to ensure messages are accessible and acceptable. Future public health campaigns should involve members of the public, and in particular people with lived experience of being at high risk of epidemic or pandemic viruses, in their design and evaluation....There is a need for more rigorous evaluations of public health campaigns encouraging vaccine uptake, measuring behavioural outcomes."

Full list of authors, with institutional affiliations: Sadie Lawes-Wickwar (University College London); Daniela Ghio (University of Salford); Mei Yee Tang (Newcastle University); Chris Keyworth (University of Manchester); Sabina Stanescu (University of Southampton); Juliette Westbrook (University of Bath); Elizabeth Jenkinson (University of West England); Angelos P. Kassianos (University College London); Daniel Scanlan (Education Support); Natalie Garnett (University of West England); Lynn Laidlaw (Public Contributor, Health Psychology Exchange Patient and Public Involvement (PPI) Group); Neil Howlett (University of Hertfordshire); Natalie Carr (Manchester Metropolitan University); Natalia Stanulewicz (De Montfort University); Ella Guest (University of West England); Daniella Watson (University of Southampton); Lisa Sutherland (Behavioural Insight); Lucie Byrne-Davis (University of Manchester); Angel Chater (University of Bedfordshire); Jo Hart (University of Manchester); Christopher J. Armitage (University of Manchester, Manchester University NHS Foundation Trust, and Health Innovation Manchester); Gillian W. Shorter (Queen's University Belfast); Vivien Swanson (University of Stirling); Tracy Epton (University of Manchester)