Restoring confidence in vaccines in the COVID-19 era

KEYWORDS:

• Vaccine hesitancy
• vaccine confidence
• health care professionals
• COVID-19 vaccine
• pandemic

Vaccine hesitancy, defined as the refusal, delay, or acceptance with doubts about vaccine usefulness and safety [1], is recognized by the World Health Organization as one of the 10 most important health threats in the world today [2]. Significant portions of populations and sub-groups around the world are reluctant about vaccination even for future COVID-19 vaccines, despite the clear public perception of the high risks associated with the pandemic. For example, in May 2020, about 25% of people in 5 surveys in France (representative samples of 1000 adults) stated that they would refuse a future vaccine against it if it were available, mainly due to safety concerns around a vaccine developed in an emergency situation [3]. Vaccine hesitancy, which is often driven by fear of adverse effects, concerns people who might swing to a position for or against a vaccine (‘the fence-sitters’). As they are likely to accept vaccines, they are a priority target of interventions to improve vaccination coverage. The determinants of vaccine hesitancy are multiple and complex; they vary over time, between countries and even within a single country. Confidence is one of its three primary determinants, together with complacency (low perceived usefulness of vaccination) and convenience (perceived constraints to access health or vaccination services) [1]. This commentary focuses on vaccine confidence, its main drivers, and how to improve it.

Confidence in vaccines depends on trust in health care professionals, health care system, science, and on socio-political context. Trust can be defined as ‘a relationship that exists between individuals, as well as between individuals and a system, in which one party accepts a vulnerable position, assuming the … competence of the other, in exchange for a reduction in decision complexity’ [4], such as providing information on the advantages and disadvantages of decisions. Trust is not uniform across all vaccines and may vary for different vaccine components (e.g., multiple antigens, adjuvants), for new vs. ‘old’ vaccines, and according to past or present vaccine-associated controversies. Trust also depends strongly on patients’ relationship with the healthcare professionals involved in vaccination: patients often seek out a professional compatible with their values and beliefs; their trust is a precondition for the delegation of vaccination and other health care decisions [5].

Healthcare professionals play a central role in confidence in vaccines and their recommendations are strong drivers of vaccine acceptance among laypeople [6]. In many countries, however, a considerable fraction of these professionals are affected by vaccine hesitancy, which in turn may be fostered by a lack of trust in health authorities. Most healthcare professionals are not really experts in vaccination: they may share with laypeople uncertainties about the benefits and safety of vaccines, and attitudes of banalization of certain vaccine preventable diseases [7–9]. This may negatively affect their own uptake of vaccines that are recommended to protect their patients and themselves, such as seasonal influenza vaccination. This may also well promote vaccine hesitancy among their patients: hesitant healthcare professionals may not address their concerns regarding vaccines appropriately. Nonetheless, because those uncertainties diminish as their medical educational level increases [10], a major investment in the initial training of healthcare professionals in the area of vaccination is necessary.

Trust in the healthcare system, the experts defining vaccination strategies, and more generally in government bodies also affects vaccine acceptance. Trust by laypeople in these distant experts, institutions, and systems depends especially on their performance. The French population’s negative perception of the government’s management of the 2009 A/H1N1 pandemic undermined confidence in the overall vaccination system and led to lower vaccination coverage against seasonal influenza for several years [11].

Vaccine hesitancy is also associated with a structural crisis of confidence in science and technology: disenchantment with science [12] results from the ‘balkanization’ of scientific knowledge, that is, the dissemination of multiple results and knowledge – all increasingly partial, conditional, provisional, and even contradictory. The scientific knowledge produced since the beginning of the COVID-19 pandemic has not escaped this balkanization, magnified by new information and communication technologies. Moreover, our daily life depends increasingly on objects, technological products (such as vaccines), and expert systems that are not under our direct scrutiny. To use them, we are constrained to trust them. This leap of faith, conceptualized by sociologist Anthony Giddens as ‘reluctant trust’, is required not only for laypeople but also for healthcare professionals [8,12]. This reluctant trust can explain why people accept or recommend a vaccine even as they are uncertain about its benefits and risks: this relative trust has become structural; it is fragile and has barely been assessed in surveys of vaccine hesitancy. Finally, exposure to criticism of vaccination, misinformation, and ‘antivax’ activists – often through social networks and the Internet – plays a major role in the crisis of trust in vaccination. Paradoxically, individuals distrust the sources of this information, but exposure to its content can induce emotional reactions and sow doubt [13].

Vaccine distrust is also enmeshed in social and political protest. Criticism of vaccines is an opportunistic hobbyhorse of opposition parties, extremist or not [6]. It may be expressed more often in disadvantaged population groups (although certainly not always) [3,14]. It may be a form of expression of social conflict, as among hospital nurses in France fighting for better working conditions and higher salaries [15]. Adherence to conspiracy theories, which a recent study in England found among almost half the population, a priori promotes mistrust against a future COVID-19 vaccine [14]. Belief in these theories, found by this study in all social categories, expresses an erosion in community-mindedness and civic participation, essential components of social cohesion [4].

As vaccine hesitancy persists, the debate about the appropriate balance of action between coercive and persuasive measures is ongoing. Some countries have expanded coercive action – making vaccination mandatory – in recent years in response to outbreaks of vaccine-preventable diseases and have seen vaccine coverage rise. This action may also have symbolic value as an affirmation of social standards in favor of vaccination. Historically, it has always raised the issue of state intrusion in the domain of individual freedom, especially concerning parents’ care of their children. It has thus been opposed by movements fighting vaccination [16]. Mandatory vaccination does not deal with the causes of vaccine hesitancy, but may instead favor it by triggering reactance: if people’s freedom to choose is reduced, they may respond with anger and seek to reassert it. Another risk of mandatory vaccination is that it furthers healthcare professionals’ disengagement from their efforts to motivate patients to be vaccinated. Accordingly, laws making vaccinations mandatory are a safety net to be reserved for disquieting epidemiological situations [16].

Educational measures are preferable from an ethical point of view and more politically acceptable. They are necessary to enable the public to understand the value of vaccination. They are difficult to implement however, and we lack evidence about the effectiveness of methods and strategies [1]. Interventions based only on the ‘knowledge-deficit model’, aimed at improving individual knowledge, do not suffice to modify vaccination behavior or increase confidence in vaccination. Multiple-component interventions, combining several levers for action, appear more effective than those with only one. Impact of (mis)information about vaccines disseminated on the Web and within social networks should be taken into account. But these sources could also be viewed as opportunities to promote positive information about vaccination.

In any case, there is no universal method applicable everywhere. Instead it is necessary to work toward the personalization of approaches by individualized communication, especially according to level of vaccine hesitancy [1]. Although mixed evidence suggests that face-to-face communication is effective, especially with healthcare professionals, scientific debate continues about the framework and style of this communication. Some work suggests that firm approaches with a presumptive discussion style may be more effective than nondirective or open approaches. Nonetheless, another approach, the motivational interview, adapted to vaccination, appears promising. This patient-centered approach based on patients’ internal motivation to change their own ambivalence, avoids rebuttals of ‘false’ opinions and listens with empathy, explores patients’ own motivations, and encourages self-efficacy. In a postpartum setting, the motivational interview has raised infant vaccination rates by 7% and reduced vaccine hesitancy by 40% [17].

In conclusion, identifying effective approaches at the individual and social levels to restore trust in vaccination is an essential issue that must be prioritized by researchers. Tailored interventions adapted to the context are needed, together with shared measurement tools and methodological guides to facilitate the sharing of knowledge. This will require a holistic approach because confidence is multidimensional, strongly anchored in the social, political, and cultural reality of each country as well as in the performance of their healthcare system. The worldwide COVID-19 crisis may have a more or less important impact on public trust in public health authorities, science, and medicine, from a country to another, according to the burden of its health and socio-economic consequences and intensity of controversies. Its repercussions on confidence in existing and future vaccines must therefore be monitored in the months and years to come as we have learned, from the management of the 2009 A/H1N1 pandemic, that it may durably affect confidence in vaccination in general [11,18].

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Author contributions

PV and ED wrote and revised the article.