Background

COVID-19 vaccines were approved for use in the general population in late 2020 and early 2021 across different countries. COVID-19 vaccination hesitancy rates in the general population have now been explored across the world and are fairly well established [1,2,3,4]. For example, in a recent systematic review, the highest rates for COVID-19 vaccine acceptance in the general population were reported in Ecuador, Malaysia, Indonesia, and China (> 90% for all countries). In contrast, the lowest rates were reported for Kuwait, Jordan, Italy, Russia, Poland, United States, and France (< 60% for all countries) [4]. In these studies, from the general population, it has been shown that COVID-19 vaccination hesitancy rates differ worldwide by perceived susceptibility to and severity of COVID-19 and several sociodemographic characteristics such as sex, age, education, income, and occupation [2,3,4,5].

Recent reports suggest that many healthcare workers (HCWs) are also hesitant about or are delaying getting the COVID-19 vaccine [6,7,8,9,10]. Some reports estimate that the rates of COVID-19 vaccination hesitancy in HCWs may be similar to rates in the general population. For example, a December 2020 Kaiser Family Foundation poll found that 29% of the HCWs were reluctant to get COVID-19 vaccines as opposed to 27% of the individuals in the general population [8]. In contrast, in an early 2021 assessment of skilled nursing facilities across the United States, more than three-fourths (77.8%) of the residents of these facilities compared to a little more than a third (37.5%) of the staff in these facilities received at least one dose of the COVID-19 vaccine [9]. These estimates are of concern even though HCWs were designated as priority groups for COVID-19 vaccination across the world [8,9,10]. Given the scattered scientific evidence and a plethora of media reports, it remains to be known to what extent and why are HCWs hesitant towards obtaining COVID-19 vaccination. Thus, the purpose of this study was to review all published scientific evidence on the extent and reasons for COVID-19 vaccination hesitancy in HCWs. Also, we explored the enabling factors for COVID-19 vaccination across the world to assimilate similarities and differences in HCWs across the world as it relates to COVID-19 vaccination acceptance or willingness.

Methods

We conducted a scoping review to assimilate scientific evidence on COVID-19 vaccine hesitancy in HCWs. A comprehensive search of the scientific literature was conducted by three independent investigators (NB, TM, JK) on PubMed, EBSCO Host, pre-print servers (e.g. medRxiv) and Google Scholar. A Boolean search strategy was employed using the following keywords: “vaccine”, “COVID-19”, “hesitancy”, “refusal”, “vaccination”, “coronavirus”, “nurse”, “doctor”, “healthcare”, “worker”, “health”, “professional”. The order of keywords was changed in repeated searches across databases to extract the final pool of relevant studies. Articles that were included in the final review were screened carefully for suitability and to identify other articles that pertained to the study topic. Additional hand searches were conducted to include articles that cited the initially selected pool of articles. COVID-19 vaccination hesitancy rates data were extracted from studies if participants were “unlikely”, “refused”, “declined”, or “disagreed” with taking a COVID-19 vaccine. Participant responses such as “unsure” and “undecided” were not counted as vaccine hesitant for assessment of COVID-19 vaccination rates among the studies included in this review. Studies finally included in the review were those that were published in the English language, between February 2020- February 2021, and included healthcare workers as sole study participants (e.g., doctors, nurses, allied health professionals, and others) or HCWs who were part of a survey from the public.

Results

The final pool of studies comprised 35 studies (9 from the USA; 4 from France; 3 from Saudi Arabia; 3 from Hong Kong/ China; 2 from Congo; 2 from Malta; 2 from Greece, 2 from Italy, 2 from Canada, and 1 each from other countries as shown in Table 1) [11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45]. The sample size of the studies ranged from 123 to 16,158 participating HCWs (average study sample = 2185 per study and a total of 76,741 participants across all studies). The prevalence of COVID-19 vaccination hesitancy worldwide in HCWs ranged from 4.3 to 72% (average rate of 22.51% hesitant individuals across studies). The type of HCWs in studies included for this review differed by age, gender, race, education, income, marital status and family structure, profession, and roles in the healthcare setting (e.g., direct patient contact versus others) [11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45]

Table 1 COVID-19 vaccination in healthcare workers: findings from review of studies worldwide

In the studies where reasons for COVID-19 vaccination hesitancy were assessed, the vast majority (> 75%) of the studies found concerns about safety, efficacy, and side effects as the top three major reasons for COVID-19 vaccination hesitancy among HCWs. Other reasons for COVID-19 vaccination hesitancy were: insufficient knowledge about the vaccines, belief that COVID-19 does not exist or is not a serious disease, speedy development of vaccines, politics surrounding vaccine development process, misinformation from social media, previous COVID-19 infection or health conditions, and mistrust in authorities, health experts, and pharmaceutical companies.

Concerning factors associated with lower COVID-19 vaccination hesitancy and higher willingness for COVID-19 vaccines, the male gender was found to be an enabling factor in the majority of the studies (25/35 = 71.4%). Older age or having a doctorate or postgraduate education were associated with higher COVID-19 vaccine acceptance rates in more than half of the studies (23/35 = 65.7%). Compliance with vaccines, confidence in vaccines, or history of influenza vaccination was found to be a predictor of COVID-19 vaccine acceptance in a little more than half of the studies (18/35 = 51.4%). Similarly, direct patient contact/ caring for COVID patients or higher perceived risk and fear of being infected with COVID-19 were associated with lower COVID-19 vaccination hesitancy in more than half of the studies (20/35 = 57.1%). Other factors associated with higher COVID-19 vaccination acceptance were: White or Asian race, higher income/education, medical risk, and chronic disease history, not being infected with COVID-19 in the past, knowledge about COVID-19 infection and disease, working in non-rural areas, and beliefs that vaccines may protect friends, family, and community members.

Discussion

The findings of this review indicate that 22.51% out of 76,471 HCWs worldwide reported COVID-19 vaccination hesitancy. The public would assume that HCWs would have no hesitancy to take the COVID-19 vaccine, given the nature of the profession of HCWs. A recent survey from the general public in the United States (n = 1055) found that 32% of the participants would not or probably not get the COVID-19 vaccine [46]. Their main concerns with the vaccine were potential side effects (60%), safety (48%), how well it works (30%), and not trusting the government (22%). These reasons for not getting vaccinated were very similar to the reasons found for HCWs in this review: concerns about safety, efficacy, and side effects of the COVID-19 vaccines. HCWs' willingness to be COVID-19 vaccinated serves an important role model function for the public. Studies have found that the public trusts physicians, hospitals, researchers, and health authorities to do the right thing regarding COVID-19. Also, studies from the general public on COVID-19 vaccination hesitancy have found that recommendations by healthcare providers are associated with lower odds for COVID-19 vaccination hesitancy [14, 29, 40, 47]. However, if HCWs continue to remain hesitant towards COVID-19 vaccines, it is unlikely that they would recommend these vaccines to the general public and ensure mass vaccinations with the available COVID-19 vaccines.

Several other sociodemographic characteristics that influence COVID-19 vaccination acceptance in the general public are also associated with COVID-19 vaccination acceptance or refusal in HCWs. For example, male HCWs were more likely to accept vaccines in this review. In the general public, it has been found that females are less likely to accept a COVID-19 vaccine and it has been postulated that this could be due to concerns about side effects such as infertility, serious side effects making them unable to take care of families, or greater susceptibility to myths and misinformation from media [3, 6, 13, 24, 40, 45]. A few studies on HCWs in this review also found higher vaccine acceptance in Whites and Asians. In the general public, COVID-19 vaccination hesitancy is well established among racial and ethnic minorities and the reasons could be similar irrespective of occupational groups (e.g., medical mistrust, history of discrimination and mistreatment in research, etc.) [3, 6, 9, 28]. Similar to findings in the general public, age was also a determinant for COVID-19 vaccination acceptance in HCWs; older HCWs were more willing to accept COVID-19 vaccines. This could be because older individuals may have higher education, greater experience in healthcare settings, greater perceived vulnerability to COVID-19 infection, or higher overall medical and health risk profiles [3, 5,6,7,8, 40]. Lower education is another factor associated with COVID-19 vaccination hesitancy in both HCWs and the general public. HCWs with lower education may not read the recent research, may have lower awareness or perceived risk of illness from COVID-19, lower past compliance with vaccinations, or may have a greater tendency to believe in community myths (e.g., conspiracy theories, injection of microchips, genetic mutation or infection from the vaccine, etc.) [6,7,8,9,10,11,12].

There is a lot of confluence for the aforementioned sociodemographic characteristics outlined in our review that associate with higher COVID-19 vaccination in HCWs. A significant proportion of HCWs in the studies reviewed were females, with lower education and income, lower perceived risk of illness and younger, and belong to racial/minority populations. Frequently, these populations are overrepresented in the healthcare workforce as frontline, essential, or direct care workers [6,7,8,9,10]. Unfortunately, these are also the populations that have been most affected by the COVID-19 pandemic with a higher number of cases and deaths related to COVID-19 [3, 6, 9, 10]. Interdisciplinary and multipronged strategies must be utilized to increase COVID-19 vaccine uptake in these populations (e.g., incentives to be vaccinated, role models and community leaders encouraging vaccinations, educational interventions, hospital-based protocols and mandates, prioritizing vaccination for these groups and making vaccine access easy, giving time off or sick leave benefits to enable vaccination etc.) [6, 7, 9, 10, 47, 48].

Unlike the general public, HCWs have an obligation to “do no harm” to patients and a “duty to care” for patients who seek their help [48]. HCWs regularly work with vulnerable populations and cannot rely solely on wearing masks or personal protective equipment to fulfill their professional obligations to their patients. Also, healthcare facilities and their managers owe legal and ethical duties to their staff and patients for a safe healthcare environment. These facilities should consider a variety of protocols, educational interventions, and access options to increase COVID-19 vaccine uptake by their staff and patients. HCWs have an overwhelming need to become vaccinated and a moral obligation to serve as role models to encourage the public and their peers to engage in preventive health behaviors such as getting vaccinated with the available COVID-19 vaccines.

Several potential limitations should be considered regarding the results of this review. The search terms and methods used to identify relevant articles may have led to the omission of some relevant articles. Our criteria for selection (e.g., studies published in English during a certain time), may have introduced unknown biases. Uniformity in the primary outcome (declining to be vaccinated) differed significantly across studies (e.g., outright refusal, unlikely to take the vaccine, declined, disagreed with taking a vaccine, etc.) and may not be appropriately aggregated. Also, if a significant proportion of those who were unsure or undecided about COVID-19 vaccines end up declining the vaccine at a different period, the rates of hesitancy would be much higher than our estimates in this review. For the studies we included in this review, there were substantial differences in study participants based on age, gender, income, education, and professional roles (e.g., physicians versus nurses versus others). Aggregates presented in this review may not appropriately represent vaccine hesitancy for any particular group. Finally, this is a scoping review and not a quantitative meta-analysis. We cannot, therefore, comment on quantitative estimates such as the weighted estimates of vaccination hesitancy accounting for sample sizes and study variations.

Conclusion

This scoping review of healthcare workers’ hesitancy to be COVID-19 vaccinated found that, on average, 22.51% out of 76,417 HCWs worldwide were hesitant about the available vaccines. Their main concerns (safety, efficacy, and side effects) were very similar to the concerns identified by the general public. Being male, older, and having more advanced education were enabling factors for the uptake of COVID-19 vaccination. Healthcare workers have a moral imperative and duty to play an important role in the acceptance of COVID-19 vaccination by the public and their healthcare colleagues. Given the high rates of COVID-19 vaccination hesitancy in this population, education and policy-based interventions should be implemented to ensure that healthcare workers are vaccinated with the available COVID-19 vaccines. Without high compliance for COVID-19 vaccination among healthcare workers, there are enormous risks to the general public as well as healthcare workers.