How can a global pandemic affect vaccine hesitancy?

KEYWORDS:

• Vaccine acceptance
• vaccine refusals
• covid-19

As did SARS or Ebola in the past, the current coronavirus disease (COVID-19) highlights the vulnerabilities of humans in front of emerging infectious diseases. Given the lack of curative treatments, containment becomes paramount until vaccines are available to prevent. COVID-19 has shown how far and how fast an emerging infectious disease can spread even with containment strategies as we are a highly mobile, interdependent world [1]. As deaths and the negative impact on economies continue to grow, the world is desperately looking for vaccines as the ultimate prevention of infection strategy so physical distancing measures, travel bans, and closure of businesses and schools can be lifted.

Researchers from universities and the private sector around the world are working hard and fast to develop vaccines against COVID-19. Currently, more than 100 vaccines are at various stages of development, with more than 10 candidates now into clinical trials in humans [2].

But once vaccines against COVID-19 are available, will everyone be willing to be vaccinated? Vaccination stands at the intersection between individual and society. It involves a balance between an individual’s decision to accept or refuse a vaccine and the benefits to public health from community immunity when large numbers are vaccinated. For optimal success, vaccination programs need a high level of uptake.

Only 1 year ago, the World Health Organization listed vaccine hesitancy, or the reluctance to receive recommended vaccines when vaccination services are available [3], as 1 of the top 10 health threats of 2019 [4]. Vaccine hesitancy is defined as ‘delay in acceptance or refusal of vaccination despite availability of vaccination services. Vaccine hesitancy is complex and context specific, varying across time, place and vaccines’ [3]. A large body of literature on vaccine hesitancy exists and highlights that it is driven by both individual factors (e.g. emotions, values, risk perceptions, knowledge, or belief) and social, cultural, political, and historical factors [5,6]. The pandemic has increased awareness of the importance of vaccines for the vast majority of people who accept vaccines, but will it sway those who are reluctant, i.e those who are vaccine hesitant? Research showed that newer vaccines generate more hesitancy [7].

Findings from cross-sectional surveys among representative samples of adults from high-income countries indicate that the vast majority would be willing to be vaccinated against COVID-19 [8–11]. However, these surveys also showed that up to one quarter would not or are unsure about COVID-19 vaccination. This is similar to the proportion of those who hesitate for routine vaccines in HICs [7].

As for all vaccines [3,12], vaccine hesitancy for COVID-19 vaccines is also likely to vary over time, in different contexts and for different subgroups. Recent experiences with the HPV vaccination programs in Denmark and Ireland have shown that even well-organized vaccination programs can be derailed rapidly when vaccine safety concerns emerge [13]. Furthermore, the experience of Ebola vaccination in several countries in Africa showed that introduction of new vaccines in the context of public health emergencies can be met with social and political resistance [14]. The pandemic can also be a window of opportunity to remind about the importance of immunization. Reports from Australia indicate higher than usual influenza vaccination rates in the midst of the COVID-19 pandemic [15].

However, many challenges lie ahead, and the launch of future COVID-19 vaccination campaigns need to be carefully prepared in order to minimize vaccine hesitancy. First, the vaccine development is being pushed faster than ever seen before. Historically, the development of a vaccine for a new pathogen takes years, if not decades. Compressing that timeline increases the odds of vaccine failure, which could have detrimental impact on acceptance of COVID vaccines – and even other vaccines [16]. This may lead to legitimate concerns among the public and the health-care providers that scientists and governments are ‘cutting corners.’ Second, many of the COVID-19 vaccine antigen carrying platforms (e.g. mRNA vaccine, adenovirus carrier vaccine, etc.) are new and have never been used in humans before engendering uncertainties about the safety and efficacy profiles of these newly developed vaccines over time. Third, the production of new COVID-19 vaccines will not meet demand in a timely fashion as billion and billion of doses are needed. Priority groups to receive COVID-19 vaccines at initial distribution stage will need to be carefully assessed to maximize public health benefits while ensuring equity, especially to some subgroups that were disproportionally affected by the SARS-CoV-2 virus. Fourth, more than one type of COVID vaccine is likely to be used within a country. The safety and efficacy profiles may vary in general, but also in different subgroups by age and/or underlying conditions. These differences may be confusing to the public and lead to increase anxiety about which is ‘best’ and is it available to me and my family. These factors create an unprecedented and particularly volatile situation for which proactive and tailored risk communication and messaging will be key. Uncertainties about vaccine safety and efficacy and how they are dealt with in pharmacovigilance studies will need to be carefully communicated. Thoughtful proactively designed risk communication is especially important given the anticipation and media hype around vaccine development. Vaccine safety is one of the main reasons for vaccine hesitancy with all vaccines [17]. Concerns about vaccine safety was a major reason why people refused to receive the pandemic H1N1 vaccine [18]. Proactive listening to concerns in different subgroups, culturally sensitive and tailored strategies to roll out the programs will be more needed than ever with these new vaccines.

Indeed, vaccine opponents are already getting prepared to fight against COVID-19 vaccination. Rallies have been held and petitions are circulating to oppose to ‘mandatory’ vaccination despite the fact that it is highly unlikely that we will have mandatory COVID-19 vaccination for the public, as not enough vaccines will be available for some time. There are also conspiracy theories being promulgated (e.g. the vaccine is a plot to insert microchips, the pandemic is not real but only to sell vaccines) are getting traction in the public [19]. Many studies already have shown that ‘anti-vaccine’ discourse has more reach and impact than pro-vaccine messages and that public health entities are often ill-equipped to counteract negative discourses about vaccines online [20,21]. The extent of the influence of online discourses against vaccination on vaccination behaviors remains to be fully understood. However, listening to comments and stories about COVID vaccination that are shared online will help inform communication tactics. While COVID vaccines are still not available, it is also essential to pursue research to better understand sociocultural factors, community dynamics, and influence of vaccine criticism that may impact COVID vaccine hesitancy [22].

As the world races to develop and test COVID-19 vaccines, we must not forget that many routine immunization services have been disrupted around the globe, putting millions of children, adolescents and adults at risk of an epidemic of measles and other vaccine-preventable diseases. Delivery of routine vaccines when health services are overwhelmed by the increase in numbers of COVID-19 cases, hospitalizations and deaths are challenging. Most countries have suspended mass polio vaccination campaign and 25 countries have postponed mass measles vaccination campaigns [23,24]. School-based vaccine programs are all on hiatus. With the ‘stay-at-home’ recommendations many parents may think that routine vaccinations are non-essential care or that it is too risky to attend health services. This can contribute to a decrease in vaccine uptake rates. A recent study showed a decrease of 19.8% in the measles, mumps, and rubella (MMR) vaccination rates in the first 3 weeks of physical distancing measures in England [25].

To sum up, while it is impossible at this point to predict the impact of the pandemic on vaccine hesitancy, it is unlikely that concerns and doubts about routine vaccines will disappear and that future COVID-19 vaccines will be accepted with eagerness by everyone. Evidence-informed strategies to improve vaccine uptake can be adapted to tackle COVID-19 vaccine hesitancy (e.g. assess barriers at local level, improve access to vaccination services, engage with community leaders, etc.) [26]. We must be proactive in understanding population and subgroup perceptions of the COVID-19 vaccines. This can be done using carefully designed surveys that do not increase misinformation [27], qualitative research, and social media listening approaches. These are needed in order to develop tailored strategies to fill information voids. Carefully designed messaging is critical as COVID-19 vaccination programs come closer to being launched to ensure informed decision-making in the public and promote acceptance. Because of the urgent need, vaccines might be distributed while clinical studies are still ongoing. The uncertainties regarding the efficacy and safety profiles of the different COVID-19 vaccines will need to be carefully communicated. Health-care providers’ recommendations for vaccination are a key driver of vaccine acceptance. It will be essential to equip front-line providers with accessible and tailored information on the different COVID vaccines to support their discussion with their patients. Health-care providers could also benefit from training on communication and relational approaches to address vaccine hesitancy [28]. Finally, we must also anticipate the ‘recovery phase’ and prepare to reach groups that will have been missed by routine vaccination programs and ensure access and vaccine acceptance for all who were missed during this pandemic. Not ensuring catch up will precipitate further epidemics of vaccine-preventable diseases.

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

ED wrote the first draft of the manuscript. NEM reviewed and edited the manuscript. Both authors have read and approved the final manuscript.