Letter to the editor
Sinda Zarrouk1 and Josef Finsterer2
1Institute Pasteur of Tunis, University of Tunis El Manar and Genomic Platform, Tunis, Tunisia. 2Neurology Department, Neurology and Neurophysiology Center, Vienna, Austria (Correspondence to:
Keywords: SARS-CoV-2, vaccination, COVID-19, income, education
Citation: Zarrouk S, Finsterer J. Does willingness to be vaccinated against SARS-CoV-2 depend solely on income? East Mediterr Health J. 2025;31(9&10):598-600. https://doi.org/10.26719/2025.31.10.598.
Received: 24/08/2025; Accepted: 12/10/2025
Copyright © Authors 2025; Licensee: World Health Organization. EMHJ is an open-access journal. This paper is available under the Creative Commons Attribution Non-Commercial ShareAlike 3.0 IGO licence (CC BY-NC-SA 3.0 IGO; https://creativecommons.org/licenses/by-nc-sa/3.0/igo).
Dear Editor,
We read with interest the article by Ramezani-Doroh et al, on a cross-sectional study of the influence of income inequality on the willingness to receive the SARS-CoV-2 vaccine (1). The authors reported that fewer participants from the low-income group than from the high-income group (33.5% vs. 49.1%) were willing to be vaccinated. Female gender, older family members and witnessing COVID-19-related deaths among relatives were the main factors that influenced the willingness to be vaccinated. In contrast, employment, previous COVID-19 infection, and a bachelor's degree had the most significant opposite effects on inequality in willingness to be vaccinated. The study is impressive, however, some points should be noted.
The first point is that the study design was based on an electronic questionnaire and electronic questionnaires have several disadvantages. They can suffer from high non-response bias; those who decide to participate may differ significantly from those who do not, which can lead to some bias in the results. Online surveys may have higher dropout rates due to factors such as survey length, unclear questions or missing response options. Other disadvantages include the possibility of survey fraud, the difficulty of reaching certain population groups, and the challenge of interpreting the nuances of responses in the absence of an interviewer (2).
The second point is that several factors that have been shown to influence willingness were not included in the analysis. Willingness may also depend on the availability of certain vaccine brands, for example (3). Some studies have shown that living without a partner, smoking, regular medication use, a high number of previously discontinued disease-modifying therapies, and dissatisfaction with the pandemic measures negatively influenced the willingness to receive SARS-CoV-2 vaccine (3). Other studies found that a higher level of education and the belief that SARS-CoV-2 vaccine would protect against infection, as well as the absence of chronic diseases, were associated with increased willingness (4).
The third point is that current medication and history of previous vaccinations were not included in the analysis. Patients who have had bad experiences with current or previous medication or previous vaccinations are less likely to consent to SARS-CoV-2 vaccination than patients who have not experienced the side effects of a medication or vaccine.
The fourth point is that it is unclear whether vaccine recipients in Islamic Republic of Iran had to pay for foreign or domestic vaccines themselves, or whether SARS-CoV-2 vaccine was funded by government health authorities regardless of the vaccine brand. Free access and free administration of the SARS-CoV-2 vaccine certainly promote willingness to vaccinate. This information is needed.
The fifth point is the discrepancy between the objectives stated in the abstract (investigation of the dependence of willingness to undergo SARS-CoV-2 vaccination on income in Iran) and the information in the methodology section, according to which only vaccinated individuals from the Hamadan Region were considered. This discrepancy could be eliminated.
In summary, we can say that willingness to be vaccinated depends not only on a person's income, but also on numerous other factors.
Funding: None.
Ethical approval: not applicable
Completing interests: None declared.
References
- Ramezani-Doroh V, Badiee N, Khoramrooz M. Income inequality and willingness to accept COVID-19 vaccination in Islamic Republic of Iran
East Mediterr Health J. 2025;31(7):436-445. https://doi.org/10.26719/2025.31.7.436. - Hunter L. Challenging the reported disadvantages of e-questionnaires and addressing methodological issues of online data collection. Nurse Res. 2012;20(1):11-20. doi: 10.7748/nr2012.09.20.1.11.c9303.
- Heidler F, Hecker M, Frahm N, Baldt J, Langhorst SE, Mashhadiakbar P, Streckenbach B, Burian K, Richter J, Zettl UK. Discrepancy between vaccination willingness and actual SARS-CoV-2 vaccination status in people with multiple Sclerosis: A longitudinal study. J Clin Med. 2025;14(11):3689. doi: 10.3390/jcm14113689.
- Liu D, Luo L, Xie F, Yu Z, Ma ZF, Wang Y, Wan Z. Factors associated with the willingness and acceptance of SARS-CoV-2 vaccine from adult subjects in China. Hum Vaccin Immunother. 2021;17(8):2405-2414. doi: 10.1080/21645515.2021.1899732.
