The authors have analyzed data of 606 hospitalized COVID-19 patients at a ICU unit and sought to determine risk factors associated with SARS-CoV-2 associated fatality. Though they tried their best to communicate their findings, the manuscript should have undergone a thorough editing by a scientist in the field of epidemiology and/or infectious diseases.

Here are some of selected comments:

- from the Abstract to the Discussion section, issue related the use of English syntax is found through the entire manuscript text;              - redundant words or terms in Introduction, Methods and Discussion;

- study design not specified, as "retrospective study" cannot be considered as research design;                                                           - unnecessary repetitions of groups of words or sentences;

- the methodology used for data analysis is unclear, in Methods section authors mention "binary logistic regression" whereas they discuss the use of multivariate logistic regression in the last section of the manuscript;

- the health indicators used as "outcome variables" are not specified.

Is the work clearly and accurately presented and does it cite the current literature?

No

If applicable, is the statistical analysis and its interpretation appropriate?

No

Are all the source data underlying the results available to ensure full reproducibility?

Partly

Is the study design appropriate and is the work technically sound?

No

Are the conclusions drawn adequately supported by the results?

Partly

Are sufficient details of methods and analysis provided to allow replication by others?

No

Reviewer Expertise:

Public health (Epidemiology, communicable diseases, environmental/occupational medicine, noncommunicable diseases, international health).

I confirm that I have read this submission and believe that I have an appropriate level of expertise to state that I do not consider it to be of an acceptable scientific standard, for reasons outlined above.

Risk Factors for Fatality of Hospitalized Patients with Coronavirus Infection-2019

The topics of this paper are interesting, though well known. The structure and content must be revised, and results have to be better explained by authors before to be reconsidered.

The title has to clarify that is a case study in Abha City, Saudi Arabia. 

Abstract has to clarify the goal, empirical results and health and social implications to face next pandemics. 

Introduction has to better clarify the research questions of this study, indicating the gap presents in literature that this study endeavors to cover, and provide more theoretical background about role of vaccination, optimal rate of vaccination, and other factors. After that authors can focus on the topics of this study to provide a correct analysis for fruitful discussion (See suggested readings that must be all read and used in the text). 

The methods of this study are not clear. The section of Materials and methods must be re-structured with the following three sections and same order:

•    Sample and data

•    Measures of variables

•    Models and Data analysis procedure. 

Results

This study offers important insights into the relationship between COVID-19 vaccination status and patient outcomes in a critical care setting. However, several limitations must be acknowledged to contextualize the findings and guide future research.

The research was conducted in a single tertiary hospital in Abha City, Saudi Arabia, which may limit the generalizability of the results. Regional differences in healthcare infrastructure, patient demographics, and treatment protocols could influence outcomes in other settings. Moreover, the retrospective design of the study introduces inherent limitations, including potential biases related to data completeness and accuracy. Since the data were extracted from existing medical records, there may have been inconsistencies or missing information that could not be controlled.

Another important limitation is the lack of detailed information regarding the type of COVID-19 vaccines administered and the time elapsed since vaccination. These factors are critical in evaluating vaccine effectiveness, especially in light of waning immunity and the emergence of new SARS-CoV-2 variants. The study also did not stratify patients based on the specific viral variants they were infected with, which could have influenced disease severity and mortality.

While multivariate logistic regression was employed to adjust for confounding variables, several potentially influential factors—such as socioeconomic status, time from symptom onset to hospital admission, and access to healthcare—were not included in the analysis. These unmeasured variables may have affected both vaccination uptake and clinical outcomes.

The study population was limited to patients admitted to the intensive care unit, inherently selecting for more severe cases. As a result, the observed case fatality rate may not reflect the broader population of COVID-19 patients, particularly those with milder disease. Furthermore, the analysis did not include long-term follow-up data, which limits understanding of post-discharge outcomes and potential long COVID complications.

Although the study observed differences in case fatality rates across ABO blood groups, the adjusted odds ratios were not statistically significant. These findings should therefore be interpreted with caution. While previous studies have suggested associations between blood group and susceptibility to infectious diseases, including SARS-CoV-2 (Batool, Durrani & Tariq 2017; Zhao et al. 2020), the evidence remains inconclusive and warrants further investigation in larger, multi-center cohorts.

The observed higher case fatality among non-Saudi patients may reflect disparities in healthcare access or delayed presentation rather than biological differences. This highlights the importance of considering social determinants of health in future analyses. Additionally, while the study confirms a high prevalence of diabetes among hospitalized patients—consistent with other reports from Saudi Arabia (Hindawi et al. 2023; Jarrar et al. 2023)—it does not explore the impact of glycemic control or other comorbidities in detail.

Discussion. 

First, authors have to synthesize the main results in a simple table to be clear for readers and then show what this study adds compared to other studies. 

Although the Results section provides a detailed description of the data collected and analyzed, there needs to be a more critical synthesis and comparison of the findings with the literature. The discussion section has to interpret and describe the significance of your findings in relation to what was already known about the research problem being investigated and explain any new understanding or insights that emerged from your research. The discussion has better to connect to the introduction through the research questions, and the literature you reviewed. The discussion clearly has to explain how this study advances these research topics.

Comment on whether the results were expected for each set of findings; go into greater depth to explain unexpected findings. Moreover, either compare your results with the findings from other studies or use the studies to support your results. 

A claim for how the results can be applied more generally, also in other countries similar to Saudi Arabia. 

Describe lessons learned, proposing recommendations that can help improve the vaccination policy with optimal rates in society, other measure of health policies because vaccination cannot be sufficient….highlighting best practices of health policy to prevent mortality and negative effects of next pandemic crises (see suggested papers to read and use).

Conclusion has to be a separate section. Conclusion has not to be a summary, but authors have to focus on manifold limitations of this study. 

In addition to the limitations already acknowledged, several other important considerations should be discussed to provide a more comprehensive understanding of the study’s constraints.

While the study explored associations between ABO blood groups and COVID-19 case fatality, the findings must be interpreted with caution. Although patients with blood group [O] exhibited the highest case fatality and those with blood group [B] the lowest, the multivariate logistic regression analysis revealed that these associations were not statistically significant. This discrepancy suggests that the observed differences may be confounded by other variables or due to sample distribution rather than a true biological effect. Previous studies have reported conflicting results regarding the role of blood groups in COVID-19 susceptibility and severity. For instance, Zhao et al. (2020) and Solhpour et al. (2020) found that individuals with blood group [A] were at higher risk, while those with blood group [O] were less susceptible. However, other investigations, including those by Jawdat et al. (2022), Nasif et al. (2022), and Latz et al. (2020), failed to establish significant associations between blood type and COVID-19 outcomes. Similarly, studies conducted in Sudan (Taha et al. 2020), Iran (Dal et al. 2021), and Turkey (Abdollahi et al. 2020) did not find meaningful correlations between Rh-type and ICU admission, mechanical ventilation, or mortality.

Another limitation lies in the lack of immunological profiling of the patients. The study did not assess antibody levels, cellular immune responses, or prior infection history, which are crucial for understanding the true protective effect of vaccination. Without this data, it is difficult to determine whether vaccinated patients had adequate immune protection at the time of hospitalization. This is particularly relevant given the evolving nature of SARS-CoV-2 and the emergence of immune-evasive variants.

Additionally, the study did not account for the potential impact of treatment protocols, medication regimens, or timing of therapeutic interventions. Variations in clinical management—such as the use of antivirals, corticosteroids, or monoclonal antibodies—could significantly influence patient outcomes but were not analyzed. This omission limits the ability to isolate the effect of vaccination and other risk factors from the influence of medical care.

The absence of data on viral load and disease progression also represents a limitation. Viral load at admission has been shown to correlate with disease severity and mortality, yet this parameter was not included in the analysis. Similarly, the study did not explore the duration of symptoms prior to hospitalization, which could reflect delays in seeking care and influence prognosis.

Furthermore, the study did not investigate behavioral or environmental factors that may contribute to disease severity, such as occupational exposure, housing conditions, or adherence to public health measures. These social determinants of health are particularly relevant in explaining disparities in case fatality between Saudi and non-Saudi patients, as highlighted by the authors.

Lastly, while the study emphasizes the protective role of vaccination, it does not explore vaccine hesitancy or barriers to vaccine access, which are critical for public health planning. Understanding why a large proportion of patients remained unvaccinated could inform targeted interventions to improve vaccine coverage and reduce mortality.

The Conclusion does not adequately discuss the theoretical and managerial implications of the study. Discuss how the gap in the literature has been addressed about the research problem.

Make sure you create 3 subsections in the Conclusion: 1) Theoretical Implications, 2) Managerial or Policy Implications, and 3) Ideas for Future Research.

In short, while the study contributes valuable data on COVID-19 outcomes in a critical care context, its findings should be interpreted within the context of these methodological and contextual limitations. A prospective designs, and a broader range of clinical and sociodemographic variables can enhance the robustness and applicability of the results.

Overall, then, the paper is interesting, but the theoretical framework is weak, and some results create confusion… structure of the paper has to be improved; study design, discussion and presentation of results have to be clarified using suggested comments.

I strongly suggest improving the paper by using all comments (suggested papers included to read and use all) that I will verify in depth,  and maybe it can be considered. 

Suggested readings of relevant papers to be read and uses to improve theoretical framework and discussion.

Elamin, M.Y., Maslamani, Y.A., Alsheikh, F.A., ... Dahlan, A.A., Gosadi, I.M. 2024. Impact of vaccination on morbidity and mortality in adults hospitalized with COVID-19 during the omicron wave in the Jazan Region, Saudi Arabia | Saudi Medical Journal, 45(2), pp. 179–187    

Agrupis, K.A., Ylade, M., Qi, Y.Y., ... Wang, X., Deen, J. 2025. Effectiveness of CoronaVac primary series with and without booster against hospitalized COVID-19 during the Omicron-predominant epidemic wave in the Philippines: a test-negative case–control study.Expert Review of Vaccines, 24(1), pp. 738–749

Coccia M. 2023. Sources, diffusion and prediction in COVID-19 pandemic: lessons learned to face next health emergency[J]. AIMS Public Health, 2023, 10(1): 145-168. doi: 10.3934/publichealth.2023012

Alkhafaji, D., Argan, R.A., Albahrani, S., ... Alhwiesh, A., Alrubaish, N. 2022. The impact of obesity on hospitalized patients with COVID-19 infection in the Eastern Province of Saudi Arabia.Journal of Medicine and Life, 2022(3), pp. 425–432    

Maleki, B., Sadeghian, A.M., Ranjbar, M. 2025. Impact of vaccination against SARS-CoV-2 on mortality risk, ICU admission rate, and hospitalization length in hospitalized COVID-19 patients: a cross-sectional study.BMC Infectious Diseases, 25(1), 144    

Coccia M. 2022. Optimal levels of vaccination to reduce COVID-19 infected individuals and deaths: A global analysis. Environmental Research, vol. 204, Part C, March 2022, Article number 112314, https://doi.org/10.1016/j.envres.2021.112314

Sábato, S., Benet, S., Rogers, A.J., ... Tierney, J., Vogel, S.E.    2025. SARS-Cov-2 vaccination strategies in hospitalized recovered COVID-19 patients: a randomized clinical trial (VATICO Trial).Scientific Reports, 15(1), 9882    2025    

Coccia, M. and Benati, I. (2024), "Effective health systems facing pandemic crisis: lessons from COVID-19 in Europe for next emergencies", International Journal of Health Governance, Vol. 29 No. 2, pp. 89-111. https://doi.org/10.1108/IJHG-02-2024-0013

Grady, C.B., Bhattacharjee, B., Silva, J., ... Krumholz, H.M., Iwasaki, A.    2025. Impact of COVID-19 vaccination on symptoms and immune phenotypes in vaccine-naïve individuals with Long COVID.Communications Medicine, 5(1), 163    

Coccia M. 2021. Pandemic Prevention: Lessons from COVID-19. Encyclopedia, vol. 1, n. 2, pp. 433-444. doi: 10.3390/encyclopedia1020036

Chuang, M.-H., Hsu, W., Tsai, Y.-W., ... Huang, P.-Y., Lai, C.-C. 2024. New-onset obstructive airway disease following COVID-19: a multicenter retrospective cohort study.BMC Medicine, 22(1), 360    

Coccia M. 2022. COVID-19 Vaccination is not a Sufficient Public Policy to face Crisis Management of next Pandemic Threats. Public Organization Review, https://doi.org/10.1007/s11115-022-00661-6

Jiang, J., Lam, K.F., Lau, E.H.Y., ... Lin, Y., Cowling, B.J. 2025. Joint analysis of time-varying effect of vaccine and antiviral drug for preventing severe complications and mortality.Scientific Reports, 15(1), 5640    

Coccia M. 2022. Improving preparedness for next pandemics: Max level of COVID-19 vaccinations without social impositions to design effective health policy and avoid flawed democracies. Environmental Research, vol. 213, October 2022, n. 113566. https://doi.org/10.1016/j.envres.2022.113566

Chong, K.C., Wei, Y., Jia, K.M., ... Yeoh, E.K., Guo, Z. 2025. SARS-CoV-2 rebound and post-acute mortality and hospitalization among patients admitted with COVID-19: cohort study.Nature Communications, 16(1), 6924    

Kargı, B. Coccia M., 2024. Rethinking the Role of Vaccinations in Mitigating COVID-19 Mortality: A Cross-National Analysis. KMU Journal of Social and Economic Research 26(47), 1173-1192, https://doi.org/10.18493/kmusekad.1529330

Alshukairi, A.N., Al-Omari, A., Al-Tawfiq, J.A., ... Qushmaq, I., Azhar, E.I.    2022. Active viral shedding in a vaccinated hospitalized patient infected with the delta variant (B.1.617.2) of SARS-CoV-2 and challenges of de-isolation.Journal of Infection and Public Health, 15(6), pp. 628–630

Is the work clearly and accurately presented and does it cite the current literature?

Partly

If applicable, is the statistical analysis and its interpretation appropriate?

Partly

Are all the source data underlying the results available to ensure full reproducibility?

Partly

Is the study design appropriate and is the work technically sound?

Partly

Are the conclusions drawn adequately supported by the results?

Partly

Are sufficient details of methods and analysis provided to allow replication by others?

Partly

Reviewer Expertise:

Public Health, Vaccination Policies, Pandemic Crises

I confirm that I have read this submission and believe that I have an appropriate level of expertise to confirm that it is of an acceptable scientific standard, however I have significant reservations, as outlined above.