Scientists identify factors triggering COVID-19 vaccine hesitancy among healthcare workers

A team of US-based scientists has recently conducted a survey to determine the willingness of healthcare workers towards coronavirus disease 2019 (COVID-19) vaccinations. A detailed report on survey findings is currently available on the medRxiv* preprint server.  


Mass vaccination is considered one of the primary measures to reduce the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and control the COVID-19 pandemic. However, a successful vaccination campaign depends on many factors, including rapid production and distribution of vaccines and public willingness to accept vaccinations. In general, vaccine acceptance can be influenced by several factors, including safety and efficacy profiles of vaccines, easy accessibility to vaccination centers, and extensive campaigning on the benefits of vaccination.

Similarly, vaccine hesitancy can be influenced largely by distrust of government policies, religious/philosophical beliefs, and uncertainties about vaccine safety. Surveys conducted in the US during the COVID-19 pandemic have revealed that 14 – 17% of the general population are unwilling to receive COVID-19 vaccines, and 10 – 15% have refused to accept vaccines.

In the current study, the scientists have explored the levels of vaccine acceptance, hesitancy, or refusal among healthcare workers in the US. Moreover, they have investigated the factors that may influence vaccine uptake behaviors.

Study design

The scientists conducted a web-based cross-sectional survey on healthcare staff working at Riverside University Health System, California. A total of 2983 healthcare workers were provided with the survey questionnaire; of whom, 789 completed the survey. The main focus of the survey was to collect information on participant's demographic characteristics, preexisting health conditions, and experience with and knowledge of COVID-19.

By assessing participants' perceptions towards COVID-19 vaccination, the scientists divided them into three groups: vaccine acceptors, hesitant, and refusers. Depending on the responses, participants were further surveyed to identify potential factors that influence their vaccination decision.

Important observations

The survey findings revealed that women and socio-economically deprived participants are more likely to be hesitant or refusers. Moreover, a higher rate of vaccine hesitancy or refusal was observed among participants with lower educational backgrounds. Compared to administrative and non-clinical staff, who were mostly vaccine-hesitant, clinical staff, including nurses and medical assistants, exhibited a higher refusal rate. In contrast, vaccine acceptance behavior was mostly observed among physicians and related health professionals.

Among reported comorbidities, hypertension was found to be less prevalent among vaccine-hesitant and refusers. In contrast, a high prevalence of asthma was observed among vaccine-hesitant. Regarding vaccination of children against common childhood diseases, about 97% of acceptors, 86% of hesitant, and 52% of refusers provided a positive answer. A significantly lower percentage of refusers mentioned receiving an annual flu shot compared to acceptors and hesitant.

Although all participants were aware of COVID-19 and its symptoms, a significantly lower level of knowledge was observed among vaccine-hesitant compared to that among acceptors and refusers.

Factors influencing vaccination decisions  

Several factors were found to independently correlate with vaccine hesitancy. These factors were gender, ethnicity, educational and socioeconomic levels, marital status, job category, weekly COVID-19 exposure, annual flu vaccination, willingness to child vaccinations, and COVID-19 related knowledge. In contrast, no correlation was observed between vaccine hesitancy and preexisting health conditions. Compared to non-Hispanic whites, Asians exhibited significantly higher hesitancy towards COVID-19 vaccination. Similarly, a comparatively higher hesitancy was observed among immunocompromised patients.  

Similar to vaccine hesitancy, several independent predictors of vaccine acceptance were identified, including age, gender, educational level, job category, body mass index (BMI), having a positive test result, hypertension, asthma, knowledge of COVID-19, annual flu vaccination, and willingness to childhood vaccinations.

Strong predictors of vaccination decisions

Gender, job category, educational level, and BMI were identified as significant independent predictors of vaccine acceptance, hesitancy, and refusal. Specifically, participants with higher educational backgrounds, male participants, and obese participants were less likely to be hesitant. In contrast, non-clinical staff were 2-times more likely to be hesitant than clinical staff.

The participants who accepted COVID-19 vaccinations mentioned that advice from healthcare professionals, encouragement from family members and friends, and individual trust on the safety and protective efficacy of vaccines are the major influencing factors for their decisions. Similarly, the majority of vaccine-hesitant reported uncertainty as to the primary influencing factor.

In contrast to acceptors and hesitant, most of the refusers mentioned that their decisions could not be influenced by any of the tested factors.

Overall, participants mentioned that their mental and physical health and wellbeing were affected by the pandemic, despite a supportive workplace environment and job-related protection. However, a comparatively lower impact on physical health was reported by refusers.

Study significance

The study identifies several factors that may potentially influence the decision of healthcare workers towards COVID-19 vaccinations. As mentioned by the scientists, these factors should be addressed carefully to increase vaccination rates among high-risk frontline workers.

*Important notice

medRxiv publishes preliminary scientific reports that are not peer-reviewed and, therefore, should not be regarded as conclusive, guide clinical practice/health-related behavior, or treated as established information.

Journal reference:
Dr. Sanchari Sinha Dutta

Written by

Dr. Sanchari Sinha Dutta

Dr. Sanchari Sinha Dutta is a science communicator who believes in spreading the power of science in every corner of the world. She has a Bachelor of Science (B.Sc.) degree and a Master's of Science (M.Sc.) in biology and human physiology. Following her Master's degree, Sanchari went on to study a Ph.D. in human physiology. She has authored more than 10 original research articles, all of which have been published in world renowned international journals.


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