Review Reports

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

To: Healthcare MDPI

Dear EIC,

Dear AE,

I hope you are doing well.

This is my review report for the manuscript ID: healthcare-4051151.

This is a mixed-methods study using interviews to examine local healthcare workers' experiences with COVID vaccination, set against the background of global health resource disparities and regional vaccine distribution challenges. I believe this can contribute some novel insights to the field. Please consider my comments for the major revision.

Comments

• Please add the P value of the main findings in the results section of the abstract.
• I’m wondering why the authors used a previous study?
• The authors should describe why “developing a randomized sampling frame was
• not possible”?
• In subsection 3.1, please remove the explanation of your methods and move it to the discussion section.
• The authors should include references for each statistical and non-statistical method in the methods section. Please note that this is a major I saw only ref#23 and #22 in this section.
• Please revise the title of section 4 as follows: Results of quantitative analysis.
• Please revise the title of section 5 as follows: Results of qualitative analysis.
• It is better to classify the study limitations and strengths as a separate subsection at the end of the discussion section.
• I saw the limitation at the end of the discussion section. What are the strengths of this study? Please put them before the limitation section.
• There is no connection between the study results and the concluding remarks and perspectives in the conclusion section. I was strongly influenced by the recommendation in the conclusion, but it should be thoroughly revised to accurately reflect the study's findings. Also, modify the conclusions of the abstract.
• Please include a figure to illustrate the study procedures, similar to a graphical abstract.

Good Luck

Author Response

Comment: This is a mixed-methods study using interviews to examine local healthcare workers' experiences with COVID vaccination, set against the background of global health resource disparities and regional vaccine distribution challenges. I believe this can contribute some novel insights to the field. Please consider my comments for the major revision.

 

Response: Thank you for your thoughtful and constructive assessment of our manuscript. We appreciate your recognition of the study’s mixed-methods approach and its potential to contribute novel insights into healthcare workers’ vaccination experiences within the context of global health resource disparities. We are grateful for your detailed comments and have carefully considered them in undertaking the major revisions to strengthen the manuscript.

Comment 1:

 

Please add the P value of the main findings in the results section of the abstract.

 

Response 1: We thank the reviewer for this suggestion. We have revised the Results section of the abstract to more accurately reflect the study’s main inferential findings and have now included p values for the primary associations reported, in line with the reviewer’s recommendation.

 

Comment 2: I'm wondering why the authors used a previous study?

Response: We thank the reviewer for this question and apologize for any confusion created by the citation of the prior study. The referenced publication is a methods-focused paper that describes the design, sampling strategy, and data collection procedures of the broader project from which the data used in this manuscript were drawn. That publication does not report any analyses or findings from the data.

 

The present manuscript reports novel analyses conducted using these data and addresses research questions that were not examined in the methods paper. The prior study is cited solely to provide transparency regarding the study design and data collection processes, rather than to reference prior analytic work. 

 

Comment 3: The authors should describe why "developing a randomized sampling frame was not possible?

 

Response 3: We thank the reviewer for requesting clarification on why a randomized sampling frame was not feasible. We have revised the Methods section to explicitly address this point. As now noted in the manuscript, a probability-based sampling approach was not possible because no comprehensive national sampling frame of healthcare workers exists in Sierra Leone. Given this structural limitation, and consistent with research conducted in low-resource and emergency contexts, we employed non-probability sampling strategies to ensure timely and feasible data collection. We believe this clarification improves transparency regarding the study’s sampling decisions.

 

Comment 4: In subsection 3.1, please remove the explanation of your methods and move it to the discussion section.

 

Response 4: We thank the reviewer for this comment. We agree that interpretive discussion of the implications and limitations of the analytic approach is more appropriately addressed in the Discussion section. Accordingly, we have revised subsection 3.1 to focus strictly on the description of the quantitative methods and statistical procedures used. Explanatory and interpretive statements regarding the rationale for conducting inferential analyses with a non-probability sample have been removed from the Methods. Core descriptions of the analytic techniques, model specification, and variable definitions have been retained in the Methods, where they are necessary for transparency.

 

Comment 5: The authors should include references for each statistical and non-statistical method in the methods section. Please note that this is a major I saw only ref#23 and #22 in this section.

 

Response 5: We thank the reviewer for highlighting the need for additional methodological references. We have revised the Methods section to include citations supporting the mixed-methods study design, the use of non-probability sampling strategies in low-resource and emergency contexts, the survey platform employed, and the statistical techniques used in the quantitative analyses. These additions strengthen the methodological grounding of the study and address the reviewer’s concern regarding adequate referencing of both statistical and non-statistical methods.

 

Comment 6: Please revise the title of section 4 as follows: Results of quantitative analysis.

Response 6: We have now modified the title based on the suggestion

 

Comment 7: Please revise the title of section 5 as follows: Results of qualitative analysis.

 

Response 7: We have modified the title based on the suggestion

 

Comment 8: It is better to classify the study limitations and strengths as a separate subsection at the end of the discussion section.

 

Response 8: We thank the reviewer for this comment. In response, we have added a strengths and limitations subsection following the Discussion. This section explicitly outlines key methodological limitations of the study, including sampling and design considerations, while also highlighting the analytic and contextual strengths of the mixed-methods approach. We believe this addition improves transparency and strengthens the interpretation of the findings.

 

Comment 9: I saw the limitation at the end of the discussion section. What are the strengths of this study? Please put them before the limitation section.

 

Response 9: Our strengths and limitation section now reports the strengths of the study followed by the limitations.

 

 

Comment 10: There is no connection between the study results and the concluding remarks and perspectives in the conclusion section. I was strongly influenced by the recommendation in the conclusion, but it should be thoroughly revised to accurately reflect the study's findings. Also, modify the conclusions of the abstract.

 

Response 10: We thank the reviewer for this important comment. We agree that the original conclusion placed disproportionate emphasis on broad normative perspectives without sufficiently grounding these reflections in the empirical findings of the study.

 

In response, we have thoroughly revised the Conclusion section to explicitly reflect the study’s quantitative and qualitative findings. The revised conclusion now emphasizes the distinction observed between initial COVID-19 vaccination uptake and subsequent booster uptake among healthcare workers, highlights the differential roles of COVID-19–related and Ebola-related experiences, and integrates evidence demonstrating how structural and informational factors shaped sustained vaccine engagement. Broader discussions of global health equity are now directly linked to these empirical patterns rather than presented as general commentary.

 

We have also revised the conclusion of the abstract to mirror these changes, ensuring consistency across the manuscript and clearly summarizing the study’s main findings and their implications. We believe these revisions strengthen the coherence of the paper and ensure that the concluding perspectives are firmly anchored in the study results.

 

 

Comment 11: Please include a figure to illustrate the study procedures, similar to a graphical abstract.

 

Response 11: We thank the reviewer for this suggestion. In response, we have added a figure illustrating the study design and data collection procedures, including the sequential qualitative and quantitative phases, sample sizes, and analytic approach. This figure provides a visual overview of the study procedures and complements the Methods section.

Reviewer 2 Report

Comments and Suggestions for Authors

I read with interest the study presented by David and colleagues on the perceptions and experiences of Sierra Leone’s healthcare workers concerning COVID-19 vaccination and booster doses. The research highlights two key findings: first, a high initial vaccine uptake (81%) primarily driven by self-protection and protecting others, though significantly overshadowed by concerns over side effects; second, a notably low booster dose uptake (34%), largely attributed to lack of awareness and unclear communication. The study aligns well with Healthcare’s aim to publish research on public health, health systems, and equity, and its focus on vaccine hesitancy in low-resource settings will be of significant interest to the journal’s readership, which includes public health practitioners and policymakers.

Despite its merits, the manuscript is riddled with issues that need to be addressed before it can be accepted for publication.

1. The justification for using a non-probability sample is presented defensively and lacks a constructive discussion on how the authors mitigated selection bias or considered the implications for generalizability. Revise the Methods section to include a more balanced and proactive discussion of the non-probability sampling strategy. Acknowledge limitations more transparently and describe any steps taken (e.g., quota sampling, diverse recruitment channels) to enhance the sample's diversity or representativeness within the accessible population, rather than solely stating it was unavoidable.
2. The presentation of Table 1 (Descriptive Statistics) is cluttered and difficult to parse, with multiple sub-questions and "select all that apply" items presented in a monolithic format. Restructure Table 1 for clarity. Consider splitting it into thematic sub-tables (e.g., Demographics, Vaccine Details, Motivations/Barriers). Ensure all percentages are calculated from the correct denominator (N for each sub-question) and add a footnote clearly explaining the calculation base for multi-select items to avoid reader confusion.
3. The qualitative results section presents participant quotes and themes but lacks depth in analysis. It reads more as a summary of concerns rather than an interpretive analysis linking quotes to broader concepts like trust, global equity, or professional identity. Strengthen the thematic analysis in Sections 5.1 and 5.2. Move beyond simply listing concerns. For each sub-theme, provide a brief analytical sentence that interprets what the quotes signifyin the context of the study's theoretical framework (e.g., how vaccine choice disparity relates to historical distrust in global health). Weave the analysis more explicitly into the narrative surrounding the quotes.
4. The transition from bivariate to multivariate findings in the quantitative results is abrupt. The text notes that multivariate analysis "muddies this clear and intuitive narrative" but does not sufficiently guide the reader through the interpretation of these more nuanced, adjusted relationships. In the narrative of Sections 4.2, provide a clearer explanation for why key bivariate associations (e.g., Ebola mortality with vaccination) become non-significant in multivariate models. Discuss potential explanations, such as confounding by other variables (e.g., region, profession) now accounted for, helping the reader understand the shift in findings.
5. The Discussion (Section 6) starts strongly but introduces the "ONE Health" concept in the final paragraph somewhat abruptly and without clear integration into the paper's main arguments about vaccine equity and communication. Either integrate the mention of ONE Health more smoothly by briefly linking it to the paper's core message of interconnectedness and equitable preparedness, or consider removing it if it feels tangential. Ensure all discussion points are directly anchored to the study's findings.
6. While limitations are noted, the critical limitation of cross-sectional design and retrospective recall for vaccination status and past experiences (Ebola, COVID-19) is underemphasized regarding its potential impact on causal inference and reliability. Expand the limitations paragraph to dedicate a specific point to the cross-sectional, retrospective nature of the data. Explicitly state that this design precludes causal conclusions about how experiences led tovaccination decisions and that recall bias may affect the accuracy of reported past events and vaccination timelines.
7. The abstract's conclusion mentions "invaluable guidance for global health initiatives" but is vague. The manuscript's conclusion calls for a "paradigm shift" but could more concretely link specific findings to actionable recommendations. Strengthen both the abstract conclusion and the final conclusion by formulating one or two specific, actionable recommendations derived directly from the key findings. For example, recommend "sustained, locally-tailored communication campaigns for boosters" or "transparent global dialogue on vaccine sourcing to build trust."
8. The flow between the quantitative and qualitative results sections is functional but could be more integrative. The paper states they are presented separately and then triangulated, but the "triangulation" in the discussion is somewhat implicit. Enhance the integrative discussion. When discussing a quantitative finding (e.g., low booster uptake due to lack of awareness), immediately follow with how the qualitative data enrich this finding (e.g., quotes showing health workers had not heard of boosters). Make the complementary value of the mixed methods more explicit throughout.

 

Comments on the Quality of English Language

The manuscript contains minor grammatical inconsistencies and slightly awkward phrasing that occasionally impede clarity (e.g., "muddy this clear and intuitive narrative," "riddled with issues" in this review's opening is intentionally stylistic but similar informality appears). Perform a thorough line-by-line edit to polish academic language and ensure consistency in tense and phrasing. Consider using professional editing services to enhance the manuscript's readability while maintaining its scholarly tone.

Author Response

Comment:

I read with interest the study presented by David and colleagues on the perceptions and experiences of Sierra Leone’s healthcare workers concerning COVID-19 vaccination and booster doses. The research highlights two key findings: first, a high initial vaccine uptake (81%) primarily driven by self-protection and protecting others, though significantly overshadowed by concerns over side effects; second, a notably low booster dose uptake (34%), largely attributed to lack of awareness and unclear communication. The study aligns well with Healthcare's aim to publish research on public health, health systems, and equity, and its focus on vaccine hesitancy in low-resource settings will be of significant interest to the journal's readership, which includes public health practitioners and policymakers.

 

Response: Thank you for your thoughtful and generous evaluation of our manuscript. We appreciate your careful reading and clear summary of the study’s key findings. We are grateful for your recognition of the manuscript’s relevance to public health, health systems, and equity, as well as its potential value to practitioners and policymakers working in low-resource settings. We have carefully considered your comments and have revised the manuscript accordingly to strengthen the clarity, rigor, and policy relevance of our findings.

 

Comment 1: The justification for using a non-probability sample is presented defensively and lacks a constructive discussion on how the authors mitigated selection bias or considered

the implications for generalizability. Revise the Methods section to include a more balanced and proactive discussion of the non-probability sampling strategy. Acknowledge limitations more transparently and describe any steps taken (e.g., quota sampling, diverse recruitment channels) to enhance the sample's diversity or representativeness within the accessible population, rather than solely stating it was unavoidable.


Response 1: Thank you for this important comment. We have revised the Methods section to provide a more balanced and constructive discussion of the non-probability sampling strategy and its implications for generalizability. In addition to clarifying why probability-based sampling was not feasible due to the absence of a comprehensive national sampling frame of healthcare workers in Sierra Leone, the revised narrative now includes additional detail on inclusion criteria and recruitment procedures. Specifically, recruitment was purposively conducted across six districts spanning different regions of the country that experienced high Ebola and COVID-19 burden and collectively account for a substantial proportion of the national healthcare workforce. Recruitment invitations were also distributed through multiple professional and facility-based channels to reach healthcare workers across varied roles and practice settings. Finally, we more transparently acknowledge the resulting limitations for external validity in the Limitations section, while emphasizing the value of the sample for understanding vaccination experiences in high-burden, resource-constrained contexts.

 

 

Comment 2: The presentation of Table 1 (Descriptive Statistics) is cluttered and difficult to parse, with multiple sub-questions and "select all that apply" items presented in a monolithic format. Restructure Table 1 for clarity. Consider splitting it into thematic sub-tables (e.g., Demographics, Vaccine Details, Motivations/Barriers). Ensure all percentages are calculated from the correct denominator (N for each sub-question) and add a footnote clearly explaining the calculation base for multi-select items to avoid reader confusion.

Response 2: Thank you for this comment. Table 1 has been revised in response to related feedback to improve clarity and readability by reorganizing variables into clearly labeled thematic sections (e.g., Demographic Characteristics, COVID-19 Vaccination Status & Motivation, COVID-19 Booster Status & Barriers, Ebola and COVID-19 Exposure Experience, and Attitudes and Beliefs Toward Vaccines). Each variable already reports its own denominator, with Ns explicitly presented as totals in the table. For items allowing multiple responses, a footnote clarifies that percentages may exceed 100%, and booster-related items are clearly identified as applying only to the vaccinated subsample. We believe these revisions address concerns regarding table organization, denominator clarity, and interpretability.

 

Comment 3: The qualitative results section presents participant quotes and themes but lacks depth in analysis. It reads more as a summary of concerns rather than an interpretive analysis linking quotes to broader concepts like trust, global equity, or professional identity. Strengthen the thematic analysis in Sections 5.1 and 5.2. Move beyond simply listing concerns. For each sub-theme, provide a brief analytical sentence that interprets what the quotes signifying the context of the study's theoretical framework (e.g., how vaccine choice disparity relates to historical distrust in global health). Weave the analysis more explicitly into the narrative surrounding the quotes.

 

 

Response 3: We have strengthened the qualitative analysis in Sections 5.1 and 5.2 by integrating brief interpretive statements within each sub-theme. These additions clarify how participant narratives reflect broader structural, informational, and historical factors shaping vaccination and booster decisions, and explicitly connect the qualitative findings to the study’s conceptual framing rather than presenting quotes descriptively.

 

 

Comment 4: The transition from bivariate to multivariate findings in the quantitative results is abrupt. The text notes that multivariate analysis "muddies this clear and intuitive narrative" but does not sufficiently guide the reader through the interpretation of these more nuanced, adjusted relationships. In the narrative of Sections 4.2, provide a clearer explanation for why key bivariate associations (e.g., Ebola mortality with vaccination) become non-significant in multivariate models. Discuss potential explanations, such as confounding by other variables (e.g., region, profession) now accounted for, helping the reader understand the shift in findings.


Response 4: Thank you for this helpful comment. We have revised Section 4.2 to improve the transition between bivariate and multivariate findings and to more clearly guide readers through the interpretation of adjusted results. Specifically, we now clarify that bivariate associations reflect unadjusted relationships, and we explicitly note that attenuation of some associations in the multivariate models likely reflects adjustment for individual, occupational, and regional characteristics, as well as interrelated outbreak-related experiences. This added narrative helps explain why certain bivariate relationships, such as Ebola-related mortality and vaccination uptake, become non-significant once relevant covariates are accounted for, thereby improving the interpretability of the multivariate findings.

 

Comment 5: The Discussion (Section 6) starts strongly but introduces the "ONE Health" concept in the final paragraph somewhat abruptly and without clear integration into the paper's main arguments about vaccine equity and communication.

Either integrate the mention of ONE Health more smoothly by briefly linking it to the paper's core message of interconnectedness and equitable preparedness, or consider removing it if it feels tangential. Ensure all discussion points are directly anchored to the study's findings.

Response 5: Thank you for this comment. In response, we have removed the mention of “ONE Health” framework from the Discussion section. Upon review, we agreed that this concept was introduced too briefly and was not sufficiently integrated into the paper’s core arguments regarding vaccine equity, access, and communication. The revised Discussion now remains fully anchored to the study’s empirical findings and focuses consistently on structural inequities in global vaccine distribution and their implications for vaccination and booster uptake in low-income settings.

 

Comment 6: While limitations are noted, the critical limitation of cross-sectional design and retrospective recall for vaccination status and past experiences (Ebola, COVID-19) is underemphasized regarding its potential impact on causal inference and reliability. Expand the limitations paragraph to dedicate a specific point to the cross-sectional, retrospective nature of the data. Explicitly state that this design precludes causal conclusions about how experiences led to vaccination decisions and that recall bias may affect the accuracy of reported past events and vaccination timelines.

Response 6: Thank you for this comment. We have expanded the Limitations section to more explicitly address the implications of the study’s cross-sectional and retrospective design. The revised text now clearly states that the design precludes causal inference regarding the relationship between prior outbreak experiences and vaccination decisions, and acknowledges the potential for recall bias and measurement error in reported vaccination status and past health events.

 

Comment 7: The abstract's conclusion mentions "invaluable guidance for global health initiatives" but is vague. The manuscript's conclusion calls for a "paradigm shift" but could more concretely link specific findings to actionable recommendations. Strengthen both the abstract conclusion and the final conclusion by formulating one or two specific, actionable recommendations derived directly from the key findings. For example, recommend "sustained, locally-tailored communication campaigns for boosters" or

"transparent global dialogue on vaccine sourcing to build trust."


Response 7: Thank you for this helpful comment. We have revised both the abstract conclusion and the manuscript conclusion to more explicitly link the study’s key findings to actionable recommendations. The abstract conclusion now specifies the need for sustained, locally tailored communication around booster doses and greater transparency in vaccine sourcing and availability, directly reflecting the quantitative and qualitative results. The manuscript conclusion was similarly revised to ground broader calls for equity and global responsibility in the study’s empirical findings.

 

 

Comment 8: The flow between the quantitative and qualitative results sections is functional but could be more integrative. The paper states they are presented separately and then triangulated, but the "triangulation" in the discussion is somewhat implicit. Enhance the integrative discussion.

When discussing a quantitative finding (e.g., low booster uptake due to lack of awareness), immediately follow with how the qualitative data enrich this finding (e.g., quotes showing health workers had not heard of boosters). Make the complementary value of the mixed methods more explicit throughout.

Response 8: Thank you for this constructive suggestion. We have revised the Discussion section to make the mixed-methods triangulation more explicit and analytically integrated. Specifically, we now directly link key quantitative findings with corresponding qualitative insights to demonstrate their complementary value. For example, quantitative evidence of low COVID-19 booster uptake is now immediately contextualized by qualitative narratives showing that many healthcare workers were willing to receive booster doses but lacked awareness, clear communication, or access. These revisions clarify how the qualitative data deepen interpretation of the quantitative results and strengthen the overall mixed-methods contribution of the study.

 

 

Comment 9: The manuscript contains minor grammatical inconsistencies and slightly awkward phrasing that occasionally impede clarity (e.g., "muddy this clear and intuitive narrative," "riddled with issues" in this review's opening is intentionally stylistic but similar informality appears). Perform a thorough line-by-line edit to polish academic language and ensure consistency in tense and phrasing. Consider using professional editing services to enhance the manuscript's readability while maintaining its scholarly tone.

 

Response 9: Thank you for this helpful suggestion. We have conducted a thorough line-by-line revision of the manuscript to improve clarity, academic tone, and consistency in tense and phrasing. In particular, we removed or revised informal or potentially ambiguous wording and tightened sentences where phrasing was awkward. Overall, these edits were intended to enhance readability and ensure the manuscript consistently reflects scholarly writing conventions throughout

Reviewer 3 Report

Comments and Suggestions for Authors

The manuscript addresses the important issue of equity in the distribution and uptake of the COVID-19 vaccine among healthcare workers in low-income settings. It provides valuable evidence for discussions on global health and vaccine equity.

The mixed-methods design is a major strength of the study as it enables the triangulation of quantitative and qualitative findings, providing a richer understanding of vaccination and booster uptake behaviours.

While the introduction is comprehensive and well-referenced, it is relatively long. Consider tightening some of the background sections to improve focus and readability while maintaining the strong theoretical framework.

The methods section is detailed and transparent. Nevertheless, clearer justification for the use of non-probability sampling and its implications for external validity could strengthen this section further.

The quantitative analyses are appropriate and clearly described. Including a brief rationale for choosing logistic regression models and discussing potential multicollinearity among predictors would enhance methodological clarity.

The results section is well organised and contains informative tables. To improve readability, repetition of numerical results presented in the tables should be minimised within the main text.

The qualitative findings are insightful and well illustrated with participant quotes. Clarifying how data saturation was determined would further strengthen the rigour of the qualitative analysis.

The discussion effectively integrates the quantitative and qualitative results, situating the findings within the broader literature. Expanding on the policy implications for global vaccine distribution mechanisms (e.g. COVAX) would enhance the paper's contribution further.

The Limitations section is appropriate and transparent. However, the potential impact of recall and social desirability biases could be discussed more explicitly.

 

Comments on the Quality of English Language

Improve your English.

Author Response

Comment:

The manuscript addresses the important issue of equity in the distribution and uptake of the COVID-19 vaccine among healthcare workers in low-income settings. It provides valuable evidence for discussions on global health and vaccine equity. The mixed-methods design is a major strength of the study as it enables the triangulation of quantitative and qualitative findings, providing a richer understanding of vaccination and booster uptake behaviours.

Response:

Thank you for your thoughtful and encouraging assessment of our manuscript. We appreciate your recognition of the study’s focus on equity in COVID-19 vaccine distribution and uptake among healthcare workers in low-income settings, as well as its relevance to broader global health discussions. We are particularly grateful for your acknowledgment of the mixed-methods design as a key strength, enabling triangulation of quantitative and qualitative findings to provide a more nuanced understanding of vaccination and booster uptake behaviors. We have carefully considered your comments and have revised the manuscript to further strengthen the integration of methods, clarify key findings, and enhance the contribution to the literature on global health and vaccine equity.

 

Comment 1: While the introduction is comprehensive and well-referenced, it is relatively long. Consider tightening some of the background sections to improve focus and readability while maintaining the strong theoretical framework.

Response: We thank the reviewer for this comment. While the overall length of the Introduction has not been substantially reduced, we have revised the section to improve focus and readability by tightening the presentation of key concepts and clarifying the theoretical framework guiding the study. Specifically, we refined the narrative to more clearly articulate the explanatory perspective informing our hypotheses and to reduce redundancy across background sections, while retaining essential contextual and theoretical content. We believe these revisions enhance coherence and strengthen the framing of the study without compromising the depth of the literature review.

 

Comment 2: The methods section is detailed and transparent. Nevertheless, clearer justification for the use of non-probability sampling and its implications for external validity could strengthen this section further.

 

Response: We thank the reviewer for this thoughtful comment. In response, we have strengthened the Methods section by explicitly justifying the use of non-probability sampling, noting the absence of a comprehensive national sampling frame of healthcare workers in Sierra Leone. In addition, the implications of this sampling approach for external validity are now clearly addressed in the Limitations section, where we note that the findings are not statistically generalizable to all healthcare workers nationally and should be interpreted accordingly. Together, these revisions improve transparency regarding both the rationale for the sampling strategy and its implications for interpretation.

 

Comment 3: The quantitative analyses are appropriate and clearly described. Including a brief rationale for choosing logistic regression models and discussing potential multicollinearity among predictors would enhance methodological clarity.

 

Response 3: We thank the reviewer for this comment. We have revised the Methods section to clarify the rationale for using logistic regression by explicitly noting the binary nature of the vaccination and booster uptake outcomes. In addition, we have strengthened the description of our modeling strategy to explain how potential multicollinearity among outbreak-related predictors was addressed. As now noted, predictors were entered sequentially and then jointly in a final model to assess individual and combined effects and to evaluate whether multicollinearity influenced the estimated associations. These clarifications enhance methodological transparency while preserving the original analytic approach.

 

 

Comment 4: The results section is well organised and contains informative tables. To improve readability, repetition of numerical results presented in the tables should be minimised within the main text.

 

Response 4: We thank the reviewer for this helpful suggestion. In response, we have revised the Results section to minimize repetition of numerical values already presented in the tables and to improve readability. Specifically, we streamlined the descriptive results by removing detailed percentage-level reporting and vaccine product breakdowns that are fully captured in Table 1, focusing instead on summarizing key patterns and contrasts. In addition, the bivariate results narrative was revised to present findings more concisely and coherently, emphasizing the significance of associations. The multivariable results were retained as presented, as they focus on interpretation of adjusted associations rather than duplicating tabulated values. We believe these revisions improve clarity while preserving the substantive content of the findings.

 

 

Comment 5: The qualitative findings are insightful and well illustrated with participant quotes. Clarifying how data saturation was determined would further strengthen the rigour of the qualitative analysis.

 

Response 5: We thank the reviewer for this helpful suggestion. We have revised the qualitative Methods section to clarify how data saturation was determined. Specifically, we now note that interviews were conducted until thematic saturation was reached, defined as the point at which no substantively new themes emerged in successive interviews, and that saturation was assessed iteratively during data collection and analysis. We believe this addition strengthens the rigor and transparency of the qualitative approach.

 

Comment 6: The discussion effectively integrates the quantitative and qualitative results, situating the findings within the broader literature. Expanding on the policy implications for global vaccine distributior mechanisms (e.g. COVAX) would enhance the paper's contribution further.

 

 

Response 6: We thank the reviewer for this constructive suggestion. In response, we have expanded the Discussion section to more explicitly articulate the policy implications of our findings for global vaccine distribution mechanisms, including the COVID-19 Vaccines Global Access (COVAX) initiative. The revised discussion situates our empirical results on high initial vaccination uptake, low booster coverage, and information gaps within the context of COVAX’s role in facilitating early vaccine access in Sierra Leone. The revision also highlights structural limitations related to sustained supply, booster availability, updated formulations, and downstream communication. We further connect these findings to broader global equity concerns and pandemic preparedness, thereby strengthening the paper’s contribution to policy-relevant discussions on global vaccine distribution.

Comment 7: The Limitations section is appropriate and transparent. However, the potential impact of recall and social desirability biases could be discussed more explicitly.

 

Response 7: We thank the reviewer for this helpful comment. In response, we have revised the Limitations section to more explicitly discuss the potential impact of recall bias and social desirability bias. Specifically, we now acknowledge that reliance on retrospective self-reports of vaccination behaviors and prior outbreak experiences may be subject to imperfect recall, and that respondents’ reporting may have been influenced by social desirability, particularly given their professional roles as healthcare workers. We believe this addition strengthens the transparency and rigor of the study’s limitations.

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

I've convinced by the revision. Thanks.

Author Response

Comment: I've convinced by the revision. Thanks

 

Response: We thank the reviewer for their thorough critic of our work and for the oppurtunity to enhance the quality of this manuscript

Reviewer 2 Report

Comments and Suggestions for Authors

I thank the authors for the effort in addressing all the raised concerns in the first round of revision.

A couple of issues remain and require their attention:

• Table 1 is, in fact, 3 tables combined, and their combination does not make sense. They should be presented separately.
• The Methods and Results subsections are poorly described and should be changed into more meaningful alternatives. For example, 2. Methods: Study design, Statistical Analysis, ..etc. 

Comments on the Quality of English Language

The sections subheadings are poorly written and should be revised.

Author Response

Comment:

I thank the authors for the effort in addressing all the raised concerns in the first round of revision.

 

Response: We thank the reviewer for their favorable outlook of our work and for the opportunity to enhance the quality of our manuscript.

 

Comment:

A couple of issues remain and require their attention:

 

Table 1 is, in fact, 3 tables combined, and their combination does not make sense. They should be presented separately.

 

Response

Thank you for pointing this out. In response, we have restructured the original Table 1 into three separate tables to improve clarity and conceptual coherence. The revised tables now present (1) participant demographic and occupational characteristics, (2) COVID-19 vaccination and booster uptake and related barriers, and (3) Ebola and COVID-19 exposure experiences. Variables related to attitudes that did not align clearly with these descriptive domains were removed. This restructuring improves readability and aligns each table more closely with its analytic purpose.

 

Comment:

The Methods and Results subsections are poorly described and should be changed into more meaningful alternatives. For example, 2. Methods: Study design, Statistical Analysis, ..etc. The sections subheadings are poorly written and should be revised.

 

Response:

Thank you for highlighting this. The numbering and key headings have now been modified in line with the suggestions. We have also reviewed the other headings for fit and accurate description of their intended narrative.