Nzubechukwu Charles Azubuike1✉, Eze Constance Nonye2, Ifeanyi Uchechukwu Victor3, and Maamah Aida Rahman4

1Department of Medicine and Surgery, Faculty of Medicine, Nnamdi Azikiwe University, Awka (Nnewi Campus). Anambra State, Awka, Nigeria

2Department of Biological Sciences, Southern Illinois University, Edwardsville, Illinois United States

3Department of Medical Laboratory Science, Delta State Hospitals Management Board, Asaba, Delta State, Nigeria

4Department of Biology, Eastern New Mexico University, United States

 Received: June 3, 2026/ Revised: July 29, 2026/Aug 2, 2026

Corresponding Author: nzubeazubuike344@gmail.com

Highlights

  • Vulnerable populations experience disproportionately higher COVID-19 morbidity and mortality due to biological and social determinants.
  • Advanced age, chronic comorbidities, poverty, and racial or ethnic disparities are major predictors of severe COVID-19 outcomes.
  • Barriers to healthcare access, testing, treatment, and vaccination continue to widen health inequities during the pandemic.
  • Institutional settings, including nursing homes and prisons, remain high-risk environments for COVID-19 transmission and mortality.
  • Equity-focused public health policies and targeted interventions are essential to reduce disparities and improve pandemic preparedness.

Abstract

 The Coronavirus Disease 2019 (COVID-19) pandemic has profoundly impacted global health, revealing stark disparities in disease burden across different population groups. Vulnerable populations including the elderly, individuals with chronic diseases, racial and ethnic minorities, socioeconomically disadvantaged communities, and those in congregate living settings have faced disproportionate risks of infection and adverse outcomes. Factors such as limited healthcare access, crowded living environments, lower health literacy, and pre-existing social inequities have intensified the challenges faced by these groups. Epidemiological data over the past years consistently demonstrate higher rates of COVID-19 morbidity and mortality among such populations, underscoring the urgent need for targeted intervention strategies. Understanding these dynamics is crucial for designing effective public health measures and reducing overall health inequities. The aim of this review was to investigate current evidence on the epidemiology of COVID-19 in vulnerable populations, focusing on risk factors, disease outcomes, and the broader public health implications. Findings from this study revealed that advanced age, underlying comorbidities (such as diabetes, hypertension, and chronic respiratory diseases), poverty, and racial/ethnic minority status are the most prominent risk factors for severe COVID-19 outcomes. Vulnerable populations also experience higher barriers to testing, treatment, and vaccination, which further exacerbate disparities. Outbreaks in institutionalized settings, such as nursing homes and prisons, have resulted in devastating mortality rates. Additionally, intersecting vulnerabilities, such as being both elderly and economically disadvantaged, compound risks. These findings highlight the complex interplay of biological, social, and structural determinants in shaping COVID-19 outcomes. In conclusion, mitigating the impact of COVID-19 among vulnerable populations requires equity-driven policies, improved healthcare access, and tailored public health interventions. Addressing these challenges is essential for reducing disparities and ensuring a more resilient response to current and future public health emergencies.

Keywords: COVID-19, Vulnerable populations, Risk factors, Health disparities, and Public health

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How to cite this article

Azubuike, N. C., Nonye, E. C., Victor, I. U., & Rahman, M. A. (2025). Epidemiology of COVID-19 in vulnerable populations: A review of the risk factors, outcomes, and implications for public health. Microbial Science Archives, 6(3), 60–75. https://doi.org/10.47587/MSA.2026.6301

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