Acceptance of COVID-19 Vaccination in Cancer Patients in Hong Kong: Approaches to Improve the Vaccination Rate

Round 1

Reviewer 1 Report

General Comments:

This paper addresses important considerations for cancer patients who have concerns about the COVID-19 vaccine. However, the measurement and analysis, especially for multi-variate statistics and the summarization of scales, is unclear. There were no tables or figures included and these are necessary for a full review. The information and study are important, especially as many countries struggle to reach “herd immunity” and perhaps limit COVID spread and further mutations.

Specific Edits and Comments:

In the abstract and throughout. When the authors refer to acceptance of COVID-19 vaccine they should refer to it as “intended acceptance” as the patients have not the vaccine.

In line 34. Instead of public educations, the text should say public education campaigns.

Lines 36-54 are a repeat of the abstract and beginning at “background” need to be cut.

Line 59 the second “has” in that sentence can be cut. For the date it should be “by the 9^th of May”

Line 63. Revise the first sentence to be “No effective treatment exists for COVID-19.”

Line 74. Vaccination effectiveness is NOT determined by uptake. Perhaps the authors mean “Vaccination effectiveness to achieve herd immunity depends on . . .”

Lines 85 and 86: change to “ . . . getting COVID-19 and more severe complications with a higher mortality . . .”

Line 93: change to “ . . . a previous study . . .”

Section 2.2 on the Questionnaire. More information needs to be provided on the measures and any scales including the responses. For line 136, the authors should cut the rest of the sentence after “was used.”

Line 139 make sure that the reference is to intended acceptance.

Lines 141-142 Should read, “. . . the intended acceptance of a COVID-19 vaccine where patients responding . . . vaccine was counted as intended acceptance.”

Line 151 How were variables selected to be predictors in the regression model?

Line 154 Association should be plural, please add an “s”.

Lines 188-189 The last sentence in section 3.2 is not clear enough. Please be specific to the variables mentioned in the measurement section and indicate in what table this information should be included.

Similarly sections 3.3 and 3.4 need to indicate where the data is displayed or provide the data points for all statements (see lines 216-17). Make sure to include test statistics (chi-square, t-tests) and significance levels for all relationships in the text. This may be on the tables/figures but these are missing. Multi-variate results need to have the statistics for the overall final model.

In the paragraph on lines 238-246, be specific to the measures. If the measure was phrased about anxiety over negative effects of the vaccine, report it that way. The numbered sentences are not parallel in grammatical structure. This restatement does not reflect some of the issues like having insurance and cancer health literacy. Reworking this paragraph is important.

The letter enumeration on page 6 needs to be corrected as all are marked “A”.

Line 252 should read, “ . . . risk of COVID-19 infection and health consequences owing . . .”

A little more description of the comparison studies on page 6 and 7 would help the reader understand the comparability of results.

Line 262. Probing is probably not the right word. Did the authors mean “putting”.

I disagree with the interpretation about comparing COVID-19 infection. In our work with cancer and other patients, we found that the patients were interested in knowing more of the science behind the vaccine and other important information. Although most infectious diseases are considered to be acute conditions, whether or not the virus will have long term consequences, like those of HIV or HPV is unknown. I agree that that patients want to understand why they are considered a vulnerable population and that this information may be convincing for getting vaccinated. Pointing out how an infection may require that treatment be stopped and may compromise treatment efforts, I agree is important and makes patients also reconsider. Patients also wanted to know about the differences in vaccines (e.g. RNA vs. other). When their questions are answered, patients are more likely to make good decisions for their health.

Line 322. The information on side effects that often subside is based on normal populations and the authors should note this to be consistent with earlier statements. Similarly, in lines 325-6, the authors also cannot rule out that there may be long term consequences of vaccination but that also holds true for getting COVID-19. Shingles is a good example in the US of a disease that older populations are familiar with and want to avoid.

Lines 330 to 332. I’m not sure what the authors are trying to say here. They should rephrase or cut.

The limits section (Lines 344 to 349) needs to be expanded. There is some sample selection. The authors should also admit that they did not ask a thorough set of questions to cover concepts that were excluded but may be explanatory. Use of a theory like the Theory of Reasoned Action may have been helpful.

Lines 359 to 360. Not only oncologist but the health provision team needs to be part of the educational campaign to improve health literacy, knowledge of science related to treatments like vaccines, and how to best protect one’s health when trying to balance different treatments. Oncologists are often not given the time to answer basic questions but instead they should be helping patients with decision making. Peer educator or community health workers should also be included to improve vaccine uptake.

Note in discussion may need to talk about more likely to have vaccine without private medical insurance. On lines 172-176 the findings indicate that those with lower levels of cancer health literacy are more willing to get vaccinated. However, on lines 217 to 217, the data indicates no relationship as similar percentages are seen in those with both high and low likelihood of getting a vaccine. Without the data presented, these findings seem contradictory. Again, on line 222, those with better cancer health literacy were more likely to have a preference for a particular vaccine. These findings, if accurate, should be explained in the discussion.

 No tables were included. Please resubmit with Tables and Figures.

Author Response

Dear Reviewers,

Thank you very much for your time and effort in reviewing our article.  We have made the amendments according to the comments.  Sincerely wish you can read the article again and wish this journal would accept the publication of our paper.

Reviewer 1:

This paper addresses important considerations for cancer patients who have concerns about the COVID-19 vaccine. However, the measurement and analysis, especially for multi-variate statistics and the summarization of scales, is unclear. There were no tables or figures included and these are necessary for a full review. The information and study are important, especially as many countries struggle to reach “herd immunity” and perhaps limit COVID spread and further mutations.

Thank you very much for your comment. The figures and tables are all in the file “Tables and figures”.

Specific Edits and Comments:

In the abstract and throughout. When the authors refer to acceptance of COVID-19 vaccine they should refer to it as “intended acceptance” as the patients have not the vaccine.

The term “intended acceptance” is now used in the revised article.

In line 34. Instead of public educations, the text should say public education campaigns. Edited.

Lines 36-54 are a repeat of the abstract and beginning at “background” need to be cut. Edited.

Line 59 the second “has” in that sentence can be cut. For the date it should be “by the 9^th of May” Edited.

Line 63. Revise the first sentence to be “No effective treatment exists for COVID-19.” Edited.

Line 74. Vaccination effectiveness is NOT determined by uptake. Perhaps the authors mean “Vaccination effectiveness to achieve herd immunity depends on . . .” Edited.

Lines 85 and 86: change to “ . . . getting COVID-19 and more severe complications with a higher mortality . . .” Edited.

Line 93: change to “ . . . a previous study . . .” Edited.

Section 2.2 on the Questionnaire. More information needs to be provided on the measures and any scales including the responses. Edited.

For line 136, the authors should cut the rest of the sentence after “was used.” Edited.

Line 139 make sure that the reference is to intended acceptance. Edited.

Lines 141-142 Should read, “. . . the intended acceptance of a COVID-19 vaccine where patients responding . . . vaccine was counted as intended acceptance.” Edited.

Line 151 How were variables selected to be predictors in the regression model? Variables were selected if p-value <0.75 in univariable analysis and by author’s knowledge and judgement.                                          

Line 154 Association should be plural, please add an “s”. Edited.

Lines 188-189 The last sentence in section 3.2 is not clear enough. Please be specific to the variables mentioned in the measurement section and indicate in what table this information should be included. Edited.

Similarly sections 3.3 and 3.4 need to indicate where the data is displayed or provide the data points for all statements (see lines 216-17). Make sure to include test statistics (chi-square, t-tests) and significance levels for all relationships in the text. This may be on the tables/figures but these are missing. Multi-variate results need to have the statistics for the overall final model. Edited.

In the paragraph on lines 238-246, be specific to the measures. If the measure was phrased about anxiety over negative effects of the vaccine, report it that way. The numbered sentences are not parallel in grammatical structure. This restatement does not reflect some of the issues like having insurance and cancer health literacy. Reworking this paragraph is important. Edited.

The letter enumeration on page 6 needs to be corrected as all are marked “A”. Edited.

Line 252 should read, “ . . . risk of COVID-19 infection and health consequences owing . . .” Edited.

A little more description of the comparison studies on page 6 and 7 would help the reader understand the comparability of results. More description on the reference studies were added.

Line 262. Probing is probably not the right word. Did the authors mean “putting”. Edited.

I disagree with the interpretation about comparing COVID-19 infection. In our work with cancer and other patients, we found that the patients were interested in knowing more of the science behind the vaccine and other important information. Although most infectious diseases are considered to be acute conditions, whether or not the virus will have long term consequences, like those of HIV or HPV is unknown. I agree that that patients want to understand why they are considered a vulnerable population and that this information may be convincing for getting vaccinated. Pointing out how an infection may require that treatment be stopped and may compromise treatment efforts, I agree is important and makes patients also reconsider. Patients also wanted to know about the differences in vaccines (e.g. RNA vs. other). When their questions are answered, patients are more likely to make good decisions for their health.

Thank you very much for your comment.  We agreed that patients should not compare COVID-19 infection with cancer.  This misconception from patients should be clarified by the oncologists.  We have discussed and pointed out this misconception from patients and wish this can help to improve the vaccination rate.  We have also added in items in the discussion part so that health care professionals can explain more to patients and relieve their anxiety.

Line 322. The information on side effects that often subside is based on normal populations and the authors should note this to be consistent with earlier statements. Similarly, in lines 325-6, the authors also cannot rule out that there may be long term consequences of vaccination but that also holds true for getting COVID-19. Shingles is a good example in the US of a disease that older populations are familiar with and want to avoid.

We have specified that those side effects are commonly seen and observations were based on normal populations. We have also discussed in the Discussion Part (B) about the long-COVID syndrome. We agreed that COVID-19 may cause long-term sequalae to the infected people.

Lines 330 to 332. I’m not sure what the authors are trying to say here. They should rephrase or cut. Deleted

The limits section (Lines 344 to 349) needs to be expanded. There is some sample selection. The authors should also admit that they did not ask a thorough set of questions to cover concepts that were excluded but may be explanatory. Use of a theory like the Theory of Reasoned Action may have been helpful.

Thank you very much for your comment.  We have added more points in the limitation part.

Lines 359 to 360. Not only oncologist but the health provision team needs to be part of the educational campaign to improve health literacy, knowledge of science related to treatments like vaccines, and how to best protect one’s health when trying to balance different treatments. Oncologists are often not given the time to answer basic questions but instead they should be helping patients with decision making. Peer educator or community health workers should also be included to improve vaccine uptake.

Thank you very much for your suggestions.  Certainly different parties should play an important role in promoting vaccination to improve the vaccination rate.  We have added in different parties in the conclusion part.

Note in discussion may need to talk about more likely to have vaccine without private medical insurance. On lines 172-176 the findings indicate that those with lower levels of cancer health literacy are more willing to get vaccinated. However, on lines 217 to 217, the data indicates no relationship as similar percentages are seen in those with both high and low likelihood of getting a vaccine. Without the data presented, these findings seem contradictory. Again, on line 222, those with better cancer health literacy were more likely to have a preference for a particular vaccine. These findings, if accurate, should be explained in the discussion.

Both medical insurance and gender showed statistically significant in univariable analysis but not significant in multivariable analysis. 

Cancer health literacy is significantly associated with preference on the type of vaccine.  It is important to have more education to the cancer patients so that they can make a better choice for their health.

No tables were included. Please resubmit with Tables and Figures.

Sorry for the confusion. All tables and figures are in another file “tables and figures” which was previously submitted.

 

We understand the limitations and shortcomings of this study.  However, the findings of this study are valuable to our cancer patients and health professionals taking care of cancer patients.  From our knowledge, this is the first article studying on the acceptance of vaccine in cancer patients which are special group facing terminal illness and are vulnerable to infection due to their illness and treatment.  We have made all amendments according to reviewers’ comments.

We sincerely wish our article can be published in this journal.

Thank you very much. And wish your journal every success.

 

Best regards,

 

Dr. Wing-Lok Chan

Clinical Assistant Professor

Department of Clinical Oncology

The University of Hong Kong

 

Reviewer 2 Report

The reviewed paper "Acceptance of COVID-19 vaccination in cancer patients in Hong Kong: approaches to improve the vaccination rate" consists of a survey of a population of cancer patients in Hong Kong regarding their willingness to accept COVID-19 vaccination. From these results, the authors make proposals to improve the vaccination rate in these patients. The intent is certainly commendable and interesting even if the data reported are representative of a specific geographical reality even if very high in number with specific characteristics difficult to apply on a general basis. In addition, the authors do not mention the specific scenario in which the survey is carried out, the rate of spread of the virus, the rate of infectivity in the general population, the measures implemented by the health service for the containment of infection, and the modality of distribution of vaccines (free or paid, compulsory or voluntary) and the organization of the vaccination campaign with related information to the population and motivations for adherence to the vaccine. These shortcomings, in addition to a few other observations, make acceptance of the paper difficult.

In detail :

1. Text from line 39 to line 54 should be deleted as it is repeated.
2. The Sinovac vaccine at the time of the investigation had not yet been approved by the WHO so the authors should have mentioned its main characteristics.
3. What kind of vaccine was offered to patients on the priority list? In the Western world, only RNA-based vaccines were offered to so-called frail patients due to age or disease.
4. The survey questionnaire had too wide a range of responses based on the number of participants
5. Tab 1 can be eliminated and assembled together with tab 2.
6. Compared to the number of patients who responded, how many patients were reluctant to accept the vaccination? Out of 660 participants, 118 accepted 512 wanted to wait, the others?
7. In sections 3.1 and 3.6 the sum of the partials exceeds the total. It can be guessed that there are patients present in more than one subgroup, but this fact creates confusion regarding the results. The patients were not initially divided into the two fundamental groups in terms of vaccine acceptance (those who accept the vaccine and those who do not). By dividing the population into the 2 groups, it was clearer to identify the variables correlated or influencing the initial choice.
8. Section 3.7 The results presented in this section reveal an important problem related to people's ability to achieve sufficient levels of knowledge and understanding of problems. In fact, it is well known that inability to understand or know a problem leads to difficulty to make any choice. It should also be discussed that the most marginalized groups in society (female gender, low level of culture, anxious-depressive problems) are often unable to make decisions even regarding their own health status.
9. Finally, there are also important shortcomings acknowledged by the authors themselves, such as the choice of a cross-sectional study, the way patients were sampled, the self-administration of the questionnaire that invalidates its objectivity, and the responses influenced by patients' expectations rather than by the assessment of reality.

Author Response

Dear Reviewers,

Thank you very much for your time and effort in reviewing our article.  We have made the amendments according to the comments.  Sincerely wish you can read the article again and wish this journal would accept the publication of our paper.

Reviewer 2

The reviewed paper "Acceptance of COVID-19 vaccination in cancer patients in Hong Kong: approaches to improve the vaccination rate" consists of a survey of a population of cancer patients in Hong Kong regarding their willingness to accept COVID-19 vaccination. From these results, the authors make proposals to improve the vaccination rate in these patients. The intent is certainly commendable and interesting even if the data reported are representative of a specific geographical reality even if very high in number with specific characteristics difficult to apply on a general basis. In addition, the authors do not mention the specific scenario in which the survey is carried out, the rate of spread of the virus, the rate of infectivity in the general population, the measures implemented by the health service for the containment of infection, and the modality of distribution of vaccines (free or paid, compulsory or voluntary) and the organization of the vaccination campaign with related information to the population and motivations for adherence to the vaccine. These shortcomings, in addition to a few other observations, make acceptance of the paper difficult.

Thank you very much for your comments.  We agreed that the points mentioned above are important.

In the revised article, we have mentioned the scenario in which the survey is carried out (in out-patient clinics in two hospitals and digital format through different cancer patient groups). The statistics of infection in Feb 2021, measures done by HK Government to improve the vaccination rate and measures to prevent the virus, the modality of distribution of the vaccines, the organisation of the vaccination campaign (HK Gov only), information provided by the HK Gov and motivation activities are now included in the Introduction paragraph.

In detail :

1. Text from line 39 to line 54 should be deleted as it is repeated. Edited
2. The Sinovac vaccine at the time of the investigation had not yet been approved by the WHO so the authors should have mentioned its main characteristics. The characteristics of the Sinovac vaccine (inactivated whole virion vaccine) are mentioned. At that time, Sinovac has not been approved by the WHO for emergency use.
3. What kind of vaccine was offered to patients on the priority list? In the Western world, only RNA-based vaccines were offered to so-called frail patients due to age or disease. Both Sinovac and BioNTech can be used by cancer patients in Hong Kong.
4. The survey questionnaire had too wide a range of responses based on the number of participants

Thank you very much for your comments.  We grouped “strongly disagree” and “disagree” into one group and “strongly agree” and “agree” into another group.

5. Tab 1 can be eliminated and assembled together with tab 2.

Table 1 is deleted and assembled into Table 2.  Detailed information in table 1 is now in Appendix 2.

6. Compared to the number of patients who responded, how many patients were reluctant to accept the vaccination? Out of 660 participants, 118 accepted 512 wanted to wait, the others?

Thank you very much for your comments.  We have added the number and percentage of patients who are not willing to have vaccination.

Actually these are two questions.  Since patients even accept vaccination, they may want to wait.

7. In sections 3.1 and 3.6 the sum of the partials exceeds the total. It can be guessed that there are patients present in more than one subgroup, but this fact creates confusion regarding the results. The patients were not initially divided into the two fundamental groups in terms of vaccine acceptance (those who accept the vaccine and those who do not). By dividing the population into the 2 groups, it was clearer to identify the variables correlated or influencing the initial choice.

Thank you very much for your comments.  Indeed these numbers cannot be added as there are several questions mentioned in these two paragraphs. We have put the responses of the participants to each question in Figure 1 and 2.  Hope the figures can tell more details about their responses.

8. Section 3.7 The results presented in this section reveal an important problem related to people's ability to achieve sufficient levels of knowledge and understanding of problems. In fact, it is well known that inability to understand or know a problem leads to difficulty to make any choice. It should also be discussed that the most marginalized groups in society (female gender, low level of culture, anxious-depressive problems) are often unable to make decisions even regarding their own health status.

Thank you very much for your comment.  We agree that majority of our participants do not have enough knowledge about the vaccine. However, in multivariable analysis, gender, HADS anxiety score, knowledge about vaccine are not significantly associated with acceptance of the vaccine. And interestingly, patients with lower cancer health literacy are more likely to have vaccination.  We presented our findings in our article but we could not give an explanation on it.

9. Finally, there are also important shortcomings acknowledged by the authors themselves, such as the choice of a cross-sectional study, the way patients were sampled, the self-administration of the questionnaire that invalidates its objectivity, and the responses influenced by patients' expectations rather than by the assessment of reality.

Thank you very much for your advice.  We have added some points in the limitation part. We admitted that this study is not able to tell the true vaccination rate (which is indeed very low as we have mentioned in our discussion part after doing a short medical notes review). However, our study did tell the reasons for the low acceptance rate of the COVID-19 vaccine.  We hope our findings can tell healthcare professionals (including oncologist, health educators, government) what cancer patients want to know and what directions they should take in order to improve the vaccination rate.

 

We understand the limitations and shortcomings of this study.  However, the findings of this study are valuable to our cancer patients and health professionals taking care of cancer patients.  From our knowledge, this is the first article studying on the acceptance of vaccine in cancer patients which are special group facing terminal illness and are vulnerable to infection due to their illness and treatment.  We have made all amendments according to reviewers’ comments.

We sincerely wish our article can be published in this journal.

Thank you very much. And wish your journal every success.

 

Best regards,

 

Dr. Wing-Lok Chan

Clinical Assistant Professor

Department of Clinical Oncology

The University of Hong Kong

 

Round 2

Reviewer 2 Report

The changes made in the text of the paper make it more understandable in purpose and make the results clearer. The discussion has also been improved.