Predictors for COVID-19 Vaccine Hesitancy in a Population-Based Cohort Study

During the COVID-19 pandemic, vaccine hesitancy was widespread. This observation is of critical importance for future tailored vaccination campaigns. The aim of this study was to characterize comprehensively those groups of persons who were unwilling to undergo COVID-19 vaccination or undecided and to understand the reasons for their hesitancy by investigating a highly-phenotyped population-based sample in Germany.

Methods

The Gutenberg COVID-19 Study (GCS) is a prospective population-based cohort study with sequential examination of 10 250 persons drawn randomly from population registration office data (response = 61%) (1). The present analysis is based on a follow-up examination from March to June 2021. The COVID-19 vaccination intention of unvaccinated individuals was assessed using the question: “If a vaccine against SARS-CoV-2 were available for you, would you get yourself vaccinated?” Responses ranged from 0 = very unlikely via 3 = undecided to 6 = very likely and were categorized into “unwilling” (0, 1, 2), “undecided” (3), or “willing to be vaccinated” (4, 5, 6, reference group). Vaccination intention was age and sex standardized with reference to the German population as of 31 December 2021 (Destatis). The attitude to COVID-19 vaccination was operationalized using the 5C scale (2), the general attitude toward vaccination using the Vaccination Attitudes Examination (VAX) scale (3). Statistical analysis was performed using R. The study was approved by the ethics committee. Participants provided written informed consent before study enrolment.

Results

Of the 9145 participants included in follow-up, data from 9139 individuals were analyzed (50.3% women, median age 57.9, interquartile range [IQR] 44.9/69.0 years). By June 2021, 50.9% had been vaccinated against COVID-19 (standardized 51.3%, 95% confidence interval [50.3; 52.4]) and 44.4% were willing to be vaccinated (standardized 43.8% [42.8; 44.9]), while 2.5% were undecided (standardized 2.5% [2.2; 2.9]) and 2.2% were unwilling to be vaccinated against COVID-19 (standardized 2.3% [2.0; 2.7]). Of those who did not participate in the follow-up, 9.7% had been undecided and 8.0% had been unwilling to be vaccinated between October 2020 and March 2021. The proportion of women and men who were undecided or unwilling to be vaccinated against COVID-19 was highest among those aged 45–54 years and lowest in those aged 75–88 years. Individuals who had received influenza or pneumococcal vaccination in 2019/2020 were substantially less likely to be undecided or unwilling to receive COVID-19 vaccination (Table). Persons with lower equivalized income, with a migration background, without arterial hypertension, but with cardiovascular disease and diabetes mellitus were more prevalent among those who were undecided. Belief in the existence of pandemic profiteers was strongly associated with refusal of COVID-19 vaccination and indecisiveness. The feeling of being well informed about COVID-19 vaccines and fear of COVID-19 were less prevalent among undecided or unwilling persons. Persons who used YouTube to source pandemic-related information were 3.9 times [2.23; 6.05] more likely to be unwilling to undergo vaccination. A subgroup analysis of persons aged 45–64 years, the age group with the highest vaccine hesitancy, revealed no substantial differences regarding the predictors. Despite having been vaccinated or expressed willingness to undergo vaccination, only 60.9% expressed confidence in the safety of the COVID-19 vaccines, against 4.2% of the undecided and 3.1% of the unwilling. The highest proportion of persons who weighing up the benefits and risks of COVID-19 vaccination was found among those who were unwilling (69.7%). Persons with COVID-19 vaccine hesitancy reported considerable distrust regarding the benefits of vaccinations in general (unwilling 54.4%, undecided 28.0%, reference group 1.3%), concerns about commercial profiteering (unwilling 51.4%, undecided 40.5%, reference group 8.2%), and preference for natural immunity (unwilling 63.0%, undecided 51.1%, reference group 14.9%). Concern about unforeseen future effects was high in all groups (unwilling 93.9%, undecided 96.4%, reference group 71.1%).

Table

Predictors of COVID-19 vaccine hesitancy

Discussion

COVID-19 vaccine hesitancy was related to sociodemographic, clinical, and pandemic-related factors, with some differences between unwilling and undecided persons. Alarmingly, persons at higher risk of a severe course of COVID-19 were more likely to be undecided or unwilling to be vaccinated, e.g., those with lower socioeconomic status, migration background, diabetes mellitus, and cardiovascular disease (4, 5). A major information deficit regarding COVID-19 vaccination and immunization in general became apparent. Concerns about safety and future impact were substantial, and mainly information-related predictors were determined for the hesitant attitude towards the COVID-19 vaccines. However, vaccine hesitancy is highly time-dependent. Owing to the vaccine prioritization strategies at that time, the majority of persons had to indicate their hypothetical vaccination intention. There is no validated German version of the VAX scale, and items reflecting belief in conspiracy theories have not been validated. In conclusion, this investigation highlights the need to target diverse populations in vaccination campaigns. It is crucial to improve public knowledge of and confidence in the benefits and safety of (COVID-19) vaccines. Physicians should be trained and ensure that they provide transparent, patient-tailored information during vaccination counseling.

Rieke Baumkötter, Simge Yilmaz, Daniela Zahn, Andreas Schulz, Jürgen H. Prochaska, Nora Hettich-Damm, Irene Schmidtmann, Alexander K. Schuster, Karl J. Lackner, Thomas Münzel, Manfred E. Beutel, Philipp S. Wild

Funding
The study was funded by the European Regional Development Fund and the Ministry of Science and Health of the State of Rhineland–Palatinate (EFRE/REACT-EU, grant nos. 84007232 and No. 84009735).

Part of this work forms part of Rieke Baumkötter’s doctoral thesis.

Conflict of interest statement

JHP has received honoraria for lectures from Bayer AG, Boehringer Ingelheim, Daiichi Sankyo GmbH, and Sanofi-Aventis GmbH as well as research grants from the Federal Ministry of Education and Research (BMBF) and the German Center for Cardiovascular Research.

IS is a shareholder of Biontech and Cureva c.

AKS has received financial support from Abbvie, Bayer, Heidelberg Engineering, Novartis, and Santen.

PSW has received grants and/or consulting fees from Bayer AG, Boehringer Ingelheim, Novartis Pharma, Sanofi-Aventis, Bayer Health Care, Daiichi Sankyo Europe, Astra Zeneca, and Diasorin. He has been the beneficiary of non-financial support from Philips Medical Systems, Diasorin, and IEM. He has received honoraria for lectures from Bayer Health Care, Pfizer Pharma, and Bristol Myers Squibb is being funded by the Federal Ministry of Education and Research (BMBF), Ministry of Science and Health of the State of Rhineland Palatinate (MWG RLP), and the Federal Institute for Occupational Safety and Health (BAuA). PSW is principal investigator of the German Center for Cardiovascular Research and principal investigator of the BMBF-funded DIASyM Research Core.

The remaining authors declare that no conflict of interest exists.

Manuscript received on 27 June 2023, revised version accepted on 16 November 2023.

Cite this as:
Baumkötter R, Yilmaz S, Zahn D, Schulz A, Prochaska JH, Hettich-Damm N, Schmidtmann I, Schuster AK, Lackner KJ, Münzel T, Beutel ME, Wild PS: Predictors for COVID-19 vaccine hesitancy in a population-based cohort study

Dtsch Arztebl Int 2023; 120: 886–7. DOI: 10.3238/arztebl.m2023.0253

References

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