Nurse holding a needle
By IHPL - December 14, 2021

By October 2021, 244 million known COVID-19 infections were recorded worldwide, with 45 million cases in the United States (U.S.) and resulting in over 736,000 deaths.1 Unprecedented global research efforts produced effective COVID-19 vaccines in record time, with the first doses becoming available in December 2020.2 Healthcare workers (HCWs) were the first group in the U.S. to be offered COVID-19 vaccinations. However, several months into the vaccination effort, many remain hesitant and unvaccinated despite increasingly stringent vaccination policies.

Vaccine hesitancy, the leading threat to global health,3 is the refusal of vaccination despite availability and accessibility. HCW vaccine hesitancy can be rooted in many factors including fears about safety and efficacy,4 preference for physiological herd immunity (i.e., natural inoculation),5 distrust in government,6 maintaining a sense of personal freedom,7 sociodemographic characteristics, and broader external or organizational factors.8

A recent scoping review of 35 studies published after vaccine authorizations found a hesitancy rate of 22.5% among 76,471 HCWs.9 Hesitancy rates among HCWs are occupation and context dependent. For instance, 96% of the practicing physicians in that study had been fully vaccinated.10 In contrast, only about a third (37.5%) of HCWs in skilled nursing facilities had been vaccinated.11

HCWs are a critical partner in moving vaccine-hesitant populations toward vaccination. HCWs are more trusted and viewed more positively than elected officials or government agencies.12 Therefore, addressing COVID-19 vaccine hesitancy among HCWs is a complex but important task in reaching herd immunity.

In our recent study published in the Vaccines journal, we evaluated the status of and attitudes toward COVID-19 vaccination of HCWs at Loma Linda University Health and Eisenhower Medical Center.13 Responses were collected via an anonymous online survey from a total of 2,491 participants, including nurses, physicians, other allied health professionals, and administrators. Among the 2491 participants that had been offered the vaccine at the time of the study, 2,103 (84%) were vaccinated. The bulk of the participants were middle-aged, college-educated White (73%) non-Hispanic women (75%), with nursing as the most represented medical occupation (35%).

We found four distinct clusters among 304 vaccine-hesitant HCWs, suggesting that the dichotomous 'anti-vaccine vs. pro-vaccine’ separation of HCWs may not be adequate in informing interventions.

Respondents grouped in cluster 1 ‘misinformed’ (38 participants) were slightly older and leaned Republican. They strongly opposed the COVID-19 vaccine, refusing to receive and/or recommend the COVID-19 vaccine. This group underestimated both the COVID-19 vaccine efficacy and COVID-19 mortality. Members of this cluster were more likely to believe several COVID-19 conspiracies (e.g., COVID-19 is a hoax). They were more likely to be subjects of disinformation from politically leaning news media.

Respondents in cluster 2 ‘uninformed’ (94 participants) tended to be the sub-group of HCWs with the greatest need for accurate and easy-to-understand vaccine information. This cluster was the second least willing to receive the COVID-19 vaccine. This group underestimated the impact of the pandemic and the efficacy of the vaccine. They tended to be less educated (60% lacking undergraduate degree), were more likely Hispanic/Latinx (47%), and worked in outpatient areas (33%) as allied health providers (60%).

Cluster 3 ‘undecided’ (86 participants) members were more open to receiving the COVID-19 vaccine, with half of the respondents unsure about vaccine receipt. Members of this cluster were predominantly White nurses and respiratory therapists working in an ICU. They understood the personal risk of exposure to the virus and knew the severity of COVID-19 disease, correctly assuming it is deadlier than seasonal flu. Participants in this cluster strongly leaned Republican.

Cluster 4 ‘unconcerned’ (86 participants) members were younger and racially diverse. This cluster is the most educated and leaned Democrat. Members of this cluster had an accurate knowledge of the vaccine efficacy and the lowest support of COVID-19 conspiracies. While hesitating to receive the vaccine themselves, respondents in this cluster were willing to recommend it to others.

Our study found diversity in vaccine hesitancy among HCWs and highlights the need for unique and targeted interventions depending on degrees, types, and causes of hesitancy. Consequently, messaging should be tailored to specific subgroups to increase the understanding of the science behind vaccines. Interventions should elicit HCWs’ concerns with empathy, and policymaking should be inclusive of vaccine-hesitant subgroups.

Author bio:

Alex Dubov

Alex Dubov, PhD

Dr. Dubov is an Associate Professor for the School of Behavioral Health. His research interests lie in applying scientifically rigorous approaches (i.e. conjoint analysis) to better understand and improve both patient and physician decision making. He is also interested in leveraging emerging technologies as innovative approaches for supporting the implementation of combination (biomedical, behavioral, and health system) interventions to prevent HIV infection among groups that are epidemiologically at high-risk for infection and whose prevention needs are complicated by their socially marginalized statuses in their communities.


  1. World Health Organization. Coronavirus Disease 2019 (COVID-19) Situation Reports. Available online: (accessed on 17 October 2021).
  2. Food and Drug Administration. COVID-19 Vaccines. Available online: (accessed on 17 August 2021).
  3. World Health Organization. Ten Threats to Global Health in 2019. Available online: (accessed on 17 August 2021).
  4. Dror, A.A.; Eisenbach, N.; Taiber, S.; Morozov, N.G.; Mizrachi, M.; Zigron, A.; Srouji, S.; Sela, E. Vaccine hesitancy: the next challenge in the fight against COVID-19. Eur J Epidemiol 2020, 35, 775-779, DOI:10.1007/s10654-020-00671-y.
  5. Fontanet, A.; Cauchemez, S. COVID-19 herd immunity: where are we. Nat Rev Immunol 2020, 20, 583-584, DOI:10.1038/s41577-020-00451-5.
  6. Paterson, P.; Meurice, F.; Stanberry, L.R.; Glismann, S.; Rosenthal, S.L.; Larson, H.J. Vaccine hesitancy and healthcare providers. Vaccine 2016, 34, 6700-6706, DOI:10.1016/j.vaccine.2016.10.042.
  7. Kirzinger, A.; Munana, C.; Brodie, M. Vaccine Hesitancy in Rural America. Available online: (accessed on 17 August 2021).
  8. Li, M.; Luo, Y.; Watson, R.; Zheng, Y.; Ren, J.; Tang, J.; Chen, Y. Healthcare workers' (HCWs) attitudes and related factors towards COVID-19 vaccination: a rapid systematic review. Postgrad Med J DOI:10.1136/postgradmedj-2021-140195.
  9. Biswas, N.; Mustapha, T.; Khubchandani, J.; Price, J.H. The Nature and Extent of COVID-19 Vaccination Hesitancy in Healthcare Workers. J Community Health DOI:10.1007/s10900-021-00984-3.
  10. American Medical Association. AMA Survey Shows Over 96% of Doctors Fully Vaccinated Against COVID-19. Avail-able online: (accessed on 17 August 2021).
  11. Gharpure, R.; Guo, A.; Bishnoi, C.K.; Patel, U.; Gifford, D.; Tippins, A.; Jaffe, A.; Shulman, E.; Stone, N.; Mungai, E.; Bagchi, S.; Bell, J.; Srinivasan, A.; Patel, A.; Link-Gelles, R. Early COVID-19 First-Dose Vaccination Coverage Among Residents and Staff Members of Skilled Nursing Facilities Participating in the Pharmacy Partnership for Long-Term Care Pro-gram - United States, December 2020-January 2021. MMWR Morb Mortal Wkly Rep 2021, 70, 178-182, DOI:10.15585/mmwr.mm7005e2.
  12. Burden, S.; Henshall, C.; Oshikanlu, R. Harnessing the nursing contribution to COVID-19 mass vaccination programmes: Addressing hesitancy and promoting confidence. J Adv Nurs 2021, 77, e16-e20, DOI:10.1111/jan.14854.
  13. Dubov, A.; Distelberg, B.J.; Abdul-Mutakabbir, J.C.; Beeson, W.L.; Loo, L.K.; Montgomery, S.B.; Oyoyo, U.E.; Patel, P.; Peteet, B.; Shoptaw, S.; Tavakoli, S.; Chrissian, A.A. Predictors of COVID-19 Vaccine Acceptance and Hesitancy among Healthcare Workers in Southern California: Not Just “Anti” vs. “Pro” Vaccine. Vaccines 2021, 9, 1428,