Who Influences the Public Intention to Get a COVID-19 Vaccine and What are the Public References and Concerns? A Population Survey in Vietnam

The coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) has resulted in massive damages to human health, wealth, and welfare [1]. COVID-19 vaccination is considered a critical component for ending the pandemic [2]. Several authorized vaccines have been used worldwide, and other vaccines are currently being tested or developed [1]. However, the success of any COVID-19 vaccination program depends on the public acceptance of the vaccine [3]. In 2019, the World Health Organization (WHO) identified 10 threats for global health including vaccine hesitancy and the risk for a pandemic, both of which the world is now facing [4]. Regarding vaccine hesitancy, it is often explained to be due to the lack of knowledge or a miscalculation of risk [5]. However, providing corrective vaccine information has been shown to be ineffective in combatting vaccine hesitancy [5]. Trust in information includes trust in the information itself and trust in those who produce and disseminate the information [6]. This suggests that vaccine hesitators mistrusted either the vaccine information or the information generators/communicators or both and thus, did not accept the vaccine [5, 7]. In respect of the latter, trust is conceptualized 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 best interests and competence of the other, in exchange for a reduction in decision complexity” [6]. It has long been documented that trust places in the system that is responsible for vaccine delivery, in the healthcare professionals who recommend and administer the vaccines, and in the government officials who develop the vaccination programs [8]. Several studies have found that mistrust of information providers, such as healthcare professionals and government officials is the key determinant of vaccine hesitancy [5, 7].

With regard to COVID-19 vaccines, studies have found that trust in the vaccines is crucial in ensuring vaccine acceptability and is critically determined by the ability of the bodies that communicate the benefits of vaccination like the governments [2]. Trust is particularly important considering the increasing number of vaccines recommended, as well as the complexity of safety and efficacy data that form the basis of vaccine recommendations, all of which are happening in case of COVID-19 [6]. Hence, it is recommended that governments and health authorities should improve communication and increase trust to increase acceptability of the COVID-19 vaccine and decrease hesitancy [9]. Given that public trust in any vaccine and vaccination program is highly variable and country-specific [6], several studies have explored public trust in the COVID-19 vaccine in several countries worldwide [1, 2, 9, 10, 11]. However, information regarding this issue is scarce in Vietnam. We considered trust in the COVID-19 vaccine information as nested within the trust held in the information source as described previously [6]. Lessons learned from previous infectious disease-related public health emergencies, such as H1N1, SARS, and MERS, emphasized the importance of trusted sources of information and guidance in disease control and prevention [12]. Hence, to strengthen public trust as Vietnam rollouts COVID-19 vaccines, this study was conducted to examine the levels of public trust in seven common groups of people who produce and/or propagate the information related to COVID-19 vaccine and vaccination. The study also aimed to identify the public references and concerns regarding COVID-19 vaccine and vaccination.

We conducted our study on 1,579 selected individuals across Vietnam, including large cities and those with a high COVID-19 burden. The distribution of age and gender in our study was comparable to those in Vietnam [26]. We observed a high level of heterogeneity in our study participants' responses to seven sources of COVID-19 vaccine recommendation. Less than half of study participants would accept the vaccine if it was recommended by senior family members, employers, and religious leaders. Although religious leaders and family members have been identified as important sources of promoting the COVID-19 vaccine [27, 28], they have a mixed influence on the public intention to get vaccinated including COVID-19 vaccine [28]. It has been found that younger respondents were more likely to accept an employer’s vaccine recommendation compared with elderly respondents, reflecting the influence of participants’ employment status on an intention to get a COVID-19 vaccine [12]. Considering this, despite 68.5% of our participants were being employed, we believe that employers had a minimal role in recommending COVID-19 vaccination among our study participants. We found that the highest positive response rates were 89.1% and 85.9%, which were attributable to recommendations made by government and physicians, respectively. It has been documented that trust in governmental policymakers is an important dimension of trust that affects the public perception of a COVID-19 vaccine [2]. Several studies found an association between higher trust in government and likelihood of willingness to receive a COVID-19 vaccine [1]. Another global survey on an intention to accept COVID-19 vaccines found that countries where acceptance exceeded 80% were Asian nations with a strong trust in central governments, such as China and South Korea [12]. The study also observed a relatively high tendency toward acceptance in middle-income countries, such as Brazil, India, and South Africa [12]. Our findings are in accordance with all these studies provided that Vietnam is also a middle-income country with a central government. Similarly, studies have found a positive impact of health professionals including physicians, nurses, and pharmacists on public trust regarding COVID-19 vaccines [2, 11, 28]. Of these sources of vaccine recommendation, physicians are the most important influencers of vaccine decision-making [29]. Although we found a high positive response rate to physicians’ recommendation, less than half of our participants intended to get a COVID-19 vaccine if it was recommended by nurses and pharmacists. Indeed, a variation in public trust in different healthcare professionals with regard to COVID-19 vaccination has been raised in the Philippine which is a comparable country [10]. Filipinos look up to physicians and consider them the most appropriate people to recommend the vaccines compared with other healthcare professionals, such as nurses [10]. Perhaps, like Filipinos, Vietnamese people have a high sense of trust and respect for physicians. Although addressing vaccine hesitancy is a multifactorial endeavor that requires more than building trust [12], our study found a high public trust in government and physicians which can contribute to public compliance with recommended actions regarding vaccine acceptance.

Most of our participants (91.5%) would wait and see what other people respond to the new vaccines before getting vaccinated. Indeed, the social acceptance of a new vaccine among peers and social network members has been identified as a dimension of trust in COVID-19 vaccines [2]. This reflects the importance of social role models in promoting COVID-19 vaccines in the community [30]. However, it has been found that the time element plays a significant role in the decision to get vaccinated among public [31]. As the public waits for a longer time period to be vaccinated, the risks of acquiring COVID-19 remains unchanged but the newly mutated virus may be more deadly, resistant, and contagious [31]. Given that it is better to have a protection than not to have one at all [31], it is pivotal to educate the public regarding the importance of having an additional protection against COVID-19 through early vaccination when the vaccine is available to them.

We found that distance from home to the vaccination centers, waiting time in vaccination centers, and travel cost influenced the intention to get a COVID-19 vaccine of only less than one-fifth of our participants. However, the nature of vaccination centers was their major concern. Most participants (88.6%) preferred to receive the vaccine at public hospitals, while less than one-third selected private hospitals, health stations, and private practices as their preferred vaccination locations. The Vietnam healthcare system has a mixture of public and private provision, in which public hospitals play a crucial role in providing health care services to the community [32]. This may explain our participants’ references regarding the vaccination centers. However, given the increasing number of private hospitals, they are an important component of the national healthcare system that provides more than 60% of outpatient services in Vietnam [33]. A rapid nationwide COVID-19 vaccine rollout cannot rely solely on public hospitals. Indeed, based on our observation, the current vaccine rollout is based on a combination of both public hospitals and field vaccination centers in Vietnam. Hence, it is crucial to examine the reason for the public reference of vaccination centers which may help in improving the public confidence in receiving the COVID-19 vaccine, regardless of the settings.

More than half of participants (57%) were unsure if the available vaccines were safe for them. Similarly, although the number of injections would influence an intention to get vaccinated of only 28.9% of participants, most participants were concerned about effectiveness (86.9%) and side effects (76.4%) of the new COVID-19 vaccines which will be available in the future. The likelihood of taking a COVID-19 vaccine has been found to be positively associated with the levels of vaccine effectiveness, demonstrating the public concern regarding vaccine effectiveness [34]. However, a study conducted in 10 low-middle-income countries in Asia (Vietnam was not included), Africa, and South America found that concern about the side effects of COVID-19 vaccine was the most common reason for hesitancy, while less than 50% of participants reported their concern regarding vaccine effectiveness [28]. It is also found that the side effects and benefits of COVID-19 vaccines are considered independently by the public [34]. Since perception of risks associated with COVID-19 vaccination is most salient among our participants, decision making is likely to be centered on the personal [35]. Therefore, it is highly likely that the COVID-19 vaccine advertising campaign in Vietnam that stresses the personal benefit would reduce hesitancy to a greater extent than collective benefits [35]. Also, since the COVID-19 vaccine effectiveness and side effects are the most important concerns, transparently informing the public of the limitations of vaccination is crucial and would not decrease their intention to get the vaccine [36].

Vaccine cost has been found to be linked to hesitancy in lower-middle income countries and may reflect lower socioeconomic status individuals [37]. Unsurprisingly, with a sizeable proportion of study participants having a Gapminder income of ≤level 3, 61.8% of all participants reported vaccine cost as their concern. At this stage, COVID-19 vaccines are provided free of charge in Vietnam by the government. However, private hospitals in Vietnam have proposed that the vaccines could be additionally distributed through these hospitals as a paid service to those who are not in the priority groups, do not want to wait for their free COVID-19 vaccination and are willing to pay for a vaccine [38]. This may explain the public concern of the vaccine cost. In addition, it is thought that follow-up booster shots, possibly annually, may be required given the unclear duration of immunity after vaccination and viral evolution and new variants [39]. If this scenario became true, providing the community with affordable vaccines would be an appropriate, long-term solution for low-resource countries like Vietnam. Hence, it is necessary to consider the vaccine cost in relation to ensuring the vaccination coverage.

Our study has some limitations. The snowball sampling technique could induce selection bias. Also, the ability to participate in an online survey of potential participants was influenced by their online reachability. However, an in-person data collection method was additionally utilized in two largest cities in Vietnam to recruit those who could not be reached online including the elderly and people without internet-enabled devices and/or internet access. These two complementary data collection methods would help expand the diversity of our study population. Our data collection methods may explain a high proportion of study participants who had a bachelor's degree or higher, although the distribution of age and gender in our study was comparable to those in Vietnam [26]. It should be noted that there are places across Vietnam in which the communities have comparable education levels, such as urban areas [26], which we predict will have similar references, concerns, and levels of trust in recommenders regarding COVID-19 vaccines.

We identified a high public trust in government and physicians regarding COVID-19 vaccine acceptance. Vaccines perceived safety and effectiveness as well as the nature of vaccination centers were the public main concerns. Hence, an effective vaccine promotion campaign should focus on the personal benefit and rely on the government and physicians. Social role models would also help reduce vaccine hesitancy. If annual vaccinations were needed, providing the community with affordable vaccines would be an appropriate, long-term solution to ensure vaccination coverage in low-resource countries like Vietnam. Further studies are needed to examine the reason for the public references of vaccination locations which may help in improving their confidence in receiving the COVID-19 vaccine, regardless of the settings.