A World without Measles and Rubella: Addressing the Challenge of Vaccine Hesitancy

"Efforts must be made to improve the implementation and availability of evidence-based strategies for addressing vaccine hesitancy to improve vaccine uptake and, ultimately, eradicate measles and rubella worldwide."

Gains in worldwide measles and rubella vaccination experienced significant setbacks during the COVID-19 pandemic due to various factors, including vaccine hesitancy. For a disease as contagious as measles, even local pockets of vaccine hesitancy leading to undervaccination can result in disease outbreaks. In general, factors influencing vaccine hesitancy are complex and involve historical, sociocultural, environmental, institutional, economic, political, and individual/group factors. These factors are further influenced by rapidly changing technologies that allow for the rapid and ubiquitous spread of information, misinformation, and disinformation. This article: (i) reviews the history and current state of measles and rubella vaccine hesitancy; (ii) provides an overview of evidence-based strategies for addressing vaccine hesitancy, including communication strategies and behavioural interventions; and (iii) explores future research directions.

As outlined here, vaccine hesitancy is primarily fueled by antivaccine activism, which has a history as long as vaccines themselves. In the 1970s and 1980s, the antivaccine movement again gained traction with the spread of both misinformation and disinformation about whole-cell pertussis vaccines and the establishment of several antivaccine organisations. Within the context of this revitalised antivaccine movement came the 1998 Lancet publication by Andrew Wakefield suggesting a link between the measles, mumps, and rubella (MMR) vaccine and autism. The journal eventually retracted the article, but the fallout from this incident resulted in significant declines in MMR vaccination. Although antivaccine sentiments and vaccine hesitancy have been studied and reported on most frequently in the United States, similar patterns have taken shape worldwide, including in low- and middle-income countries (LMICs).

The article then: shares definitions of vaccine hesitancy, confidence, acceptance, and refusal; describes common determinants of vaccine hesitancy; and looks at vaccine hesitancy and confidence measures that have been developed.

In response to the challenge of vaccine hesitancy, over the past several decades, many communication strategies have been recommended or implemented. The article offers an overview of strategies with the most robust evidence that are most commonly used, including:

• Healthcare professional communication strategies - Establishing an honest dialogue, actively listening, and welcoming questions are all critical to the vaccination discussion. The following strategies have evidence supporting their effectiveness in improving vaccine uptake:
  • Providing a strong and high-quality recommendation;
  • Using the presumptive format for initiating vaccine communication ("your daughter is due for three shots today");
  • Pursuing adherence despite initial parental reluctance; and
  • Using motivational interviewing (MI) for parents or patients who express hesitancy. MI is a patient-centred approach to enhancing behaviour change by leveraging a patient's inherent motivations.
  Other proposed strategies exist with limited evidence to date, including: (i) health professionals using their own experiences with vaccine-preventable diseases or vaccines, (ii) mentioning strategies available to minimise the pain associated with vaccination, and (iii) bundling all vaccines that a child is eligible for at a visit with a single recommendation. In addition, in LMICs, several studies have demonstrated that trained community members can use vaccine communication strategies to improve vaccine acceptance. Finally, healthcare professionals should be prepared to answer vaccine-related misinformation or myths.
• Individual communication strategies - While individual or tailored communication strategies such as apps and web-based interventions have been found to have mixed success in improving vaccine uptake, many of these tools have been shown to improve vaccine knowledge, attitudes, or beliefs. In addition to demonstrating positive effects on vaccine uptake, issues with dissemination, equity, and sustainability of these tools must be addressed.
• Mass communication strategies - Despite a lack of robust evidence, different mass communication strategies have been recommended, including the promotion of vaccines from healthcare professionals or other trusted messengers, the use of influencers or celebrities, using narratives, specifically targeting parents, and framing messages in a way that optimises vaccination behaviour change. The need for evidence-based strategies to address the spread of mis/disinformation through mass communication has been identified as a public health priority and is a critical area of future research.

Beyond communication strategies to improve vaccine acceptance, multiple healthcare system, organisational, and public health strategies improve vaccine uptake. These strategies may not be intended to address vaccine hesitancy directly; however, they may effectively overcome low to moderate levels of vaccine hesitancy by lowering or incentivising the activation energy required for vaccination. Selected examples include:

• Reminder and recall systems, which encompass various methods to identify and remind or notify individuals or parents when vaccines are due;
• High-quality vaccination services such as health professionals with adequate training on vaccine communication and healthcare systems or organisations that can use evidence-based methods to promote vaccination; and
• Incentives and requirements to improve vaccine uptake that are evidence-based and grounded in behavioural science.

The researchers stress that these strategies should not be viewed as standalone or immutable. These strategies are best applied in combination and must be tailored to the unique contexts of the communities in which they are being used. In addition, the evidence for these strategies continues to evolve, as do the recipients of these strategies and the context in which they are delivered.

Going forward, major measles and rubella vaccine hesitancy research needs fall into one of three significant categories of research priorities: (i) further describing the epidemiology and the social and behavioural determinants of vaccine hesitancy, (ii) building the evidence for interventions to improve vaccine uptake, and (iii) expanding research into LMICs countries and marginalised communities.

In concluding, the researchers stress that "The strategies discussed in this article are significantly influenced by the social determinants of health, including equitable access to affordable and quality healthcare services...The availability of health professionals skilled at culturally relevant vaccine communication, health systems with the infrastructure to implement vaccine uptake strategies, health insurance coverage, and reduced or no-cost preventive care services influence the success of vaccine-hesitancy interventions. Tackling these barriers must involve deeper collaboration between healthcare providers, health system leaders, public health professionals, policymakers, and community leaders."