|Year : 2022 | Volume
| Issue : 2 | Page : 21-27
Psychological antecedent of Coronavirus vaccination: An observational study in India
Renu Bala1, Amit Srivastava1, Ashish Kumar Dixit2, Meenakshi Shriwas3, Ravi Bhaskar4
1 Regional Research Institute for Homoeopathy, Imphal East, Manipur, India
2 Department of AYUSH, All India Institute of Medical Sciences, Bhopal, Madhya Pradesh, India
3 Department of Materia Medica, Rajasthan Vidyapeeth Homoeopathic Medical College and Hospital, Udaipur, Rajasthan, India
4 Interventional Pulmonologist, Dr Ravi Bhaskar Clinic, Lucknow, Uttar Pradesh, India
|Date of Submission||01-Jan-2022|
|Date of Decision||22-Feb-2022|
|Date of Acceptance||22-Feb-2022|
|Date of Web Publication||20-May-2022|
Dr. Renu Bala
Regional Research Institute for Homoeopathy, New Checkon, Opposite Tribal Colony, Imphal East - 795 001, Manipur
Source of Support: None, Conflict of Interest: None
Background: In December 2019, severe acute respiratory syndrome coronavirus 2, was identified as the causative agent of coronavirus disease 2019 (COVID-19). As a part of control measures against COVID-19, vaccination started in India from January 16, 2021. People's hesitancy may become an important challenge in the immunization campaign against COVID-19. This study aimed to assess the confidence of the general public and acceptance of the vaccines in India. Materials and Methods: A web-based cross-sectional survey was conducted between February 21, 2021, and March 10, 2021, by Google Forms utilizing a snowball sampling method. The psychological antecedents of vaccination for COVID-19 in India were assessed using a 15-item (3 items per antecedent) 5C scale. Results: The study received 720 responses, out of which 466 (64.72%) participants were willing to accept the CoV vaccines. Data were analyzed using STATCRAFT online statistical software version 2.0 (Bangalore, Karnataka, India). The participants who expressed more confidence in vaccines (odds ratio [OR] =1.818, P < 0.001) and who took a calculated decision (OR = 1.183, P = 0.001) were more likely to accept CoV vaccines while the participants who were complacent (OR = 0.852, P < 0.001) and who took collective responsibility (OR = 0.891, P = 0.033) were less likely to accept CoV vaccines. Conclusion: The findings of this study point to the importance of confidence, constraints, and calculation for vaccines among the Indian population, so that policymakers can monitor the acceptance for the vaccines and can plan future strategies to address hesitancy issues more effectively.
Keywords: Coronavirus disease-2019, psychological antecedents, public health, vaccination coverage, vaccination refusal, vaccines
|How to cite this article:|
Bala R, Srivastava A, Dixit AK, Shriwas M, Bhaskar R. Psychological antecedent of Coronavirus vaccination: An observational study in India. J Prim Care Spec 2022;3:21-7
|How to cite this URL:|
Bala R, Srivastava A, Dixit AK, Shriwas M, Bhaskar R. Psychological antecedent of Coronavirus vaccination: An observational study in India. J Prim Care Spec [serial online] 2022 [cited 2022 Jun 27];3:21-7. Available from: https://www.jpcsonline.org/text.asp?2022/3/2/21/345642
| Introduction|| |
Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 has spread rapidly throughout the world and was declared a pandemic in March 2020 by the World Health Organization. COVID-19 mass vaccination has emerged as a crucial preventive strategy which was first made available in India on January 16, 2021, and was subsequently ramped up in response to an increase in cases beginning in April 2021. In India, two vaccines were approved for restricted emergency use namely, Covishield manufactured by Serum Institute of India under license from AstraZeneca (adenovirus vectored ChAdOx1 nCoV-19 vaccine– AZD1222) and Covaxin (BBV152) manufactured by Bharat Biotech together with the Indian Council of Medical Research. During the first phase, health-care workers and frontline workers were targeted for vaccination, and from March 1, 2021, onward, it was extended to people over 60 years of age and those with comorbidities aged 45–59 years.
The COVID-19 pandemic with reviving waves has resulted in the implementation of lockdowns and the restriction on societal livelihood. Vaccines might be the tool to end this health and global economic crisis. Apart from the development along with testing the efficacy of vaccines and their large-scale manufacturing and distribution, building the confidence of the general public to accept the vaccines is also one of the challenges to achieve herd immunity.
The vaccine coverage rate among the population is essential for a successful immunization program. While preliminary data indicate that the approved vaccines are safe and effective, long-term efficacy and some side effects are largely unknown. The acceptance of the new vaccine remains uncertain, hence vaccine hesitancy may become an important challenge in the immunization campaign against COVID-19., The psychological factors related to the pandemic shape the attitude of an individual toward COVID-19 vaccination. Lack of awareness about the COVID-19 vaccines and apprehension about their adverse effects are the cause of low vaccine acceptance. The primary care physicians can play a significant role in allaying fears related to a novel vaccine and spreading awareness for COVID-19 vaccination.
With this backdrop, we had undertaken an observational study, which is aimed to research the beliefs and barriers related to COVID-19 vaccination among the general population in India. Relevant psychological concepts, such as attitude, perceived personal health status and invulnerability, self-control, preference for deliberation, and communal orientation assessed among the general population, will help government officials and policymakers of India to understand the issues that need to be addressed for successfully conducting mass vaccination all around the country by acquiring measures to reach out to people clearing their doubts and fear regarding the COVID vaccine.
| Materials and Methods|| |
A descriptive, web-based cross-sectional survey was conducted to assess the psychological antecedents of vaccination for COVID-19 among the general population of India by using Google Forms (docs.google.com/forms). The study was conducted between February 21, 2021, and March 10, 2021.
Participants and procedure
The study included participants above 18 years of age from all the three sexes residing in any state of India and willing to give informed consent. The present study was an observational study that proposed no fixed sample for the study. The online survey questionnaire was distributed to the general population through social media platforms such as Facebook® and WhatsApp® and they were further requested to forward the study form to their group and known contacts. Thus, a snowball sampling method was utilized for this study. The development and reporting of the survey followed the Checklist for Reporting Results of Internet E-Survey guidelines.
A Google Forms was created for the survey, which included three sections. The first section included a brief description of the survey with the consent of the participants at its beginning. The second part collected sociodemographic details of the individual participant such as age, gender, residing state, district and type of area, level of education, marital status, and occupation. Other information such as presence of any preexisting medical condition, source of information on COVID-19 vaccines, any last 5-year history of vaccination for flu/influenza, history of infection or tested positive for COVID-19, any alternative practice to vaccinate adopted, and participant willingness to get vaccinated for coronavirus were also collected.
The third section consists of 15 items to capture responses to specific questions based on the 5C scales. It is a valid, effective, and economical tool to assess the psychological antecedents of vaccination. The 5C scale offers a validated English scale to assess the antecedents with an extended 15-item scale (3 items per antecedent). The 5C subscales correlated with relevant psychological concepts, such as attitude (confidence), perceived personal health status and invulnerability (complacency), self-control (constraints), preference for deliberation (calculation), and communal orientation (collective responsibility), among others. Each item is rated on a 3-point Likert scale (1 = disagree, 2 = neutral, and 3 = agree). For the scoring, a mean score is calculated across items per antecedent. Each item with (R) is reverse-coded.,
The data from Google Forms were automatically stored in a spreadsheet on Google Drive. Data were assessed and statistically analyzed after the completion of the study. Fully completed questionnaires were extracted for cleaning and were analyzed using STATCRAFT online statistical software version 2.0 (Bangalore, Karnataka, India). The frequency and percentage of sociodemographic characteristics of the study participants were described. The Shapiro–Wilk test indicated that the data was not normally distributed (P < 0.001). The median and interquartile range (IQR) for age and 5C questionnaire was presented as descriptive analysis. The Chi-square test was used to find the significant difference in the willingness to accept CoV vaccines based on sociodemographic characteristics of the participants. Mann–Whitney U-test was performed to assess the significant difference in willingness to accept CoV vaccines after applying the 5C model. Binary logistic regression analysis was performed to identify factors significantly associated with the acceptance of CoV vaccines. Odds ratio (OR) and their 95% confidence interval were used to quantify the associations between factors and CoV vaccine acceptance. The statistical significance level was set at P < 0.05.
| Results|| |
The study received 720 responses and 50.83% (N = 366) of the study participants were female. The median age of the participants was 28 years ([IQR] = 17.25), with the highest participation recorded from the age group 18–25 years (N = 310, 43.06%). The majority of participants were unmarried (N = 379, 52.64%) and lived in urban areas (N = 472, 65.56%). Most of the participants were graduates (N = 298, 41.396%) and 36.25% (N = 261) of the participants were health-care workers by profession [Table 1].
|Table 1: Sociodemographic characteristics of the study population and willingness to take coronavirus vaccine|
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Overall 466 (64.72%) participants were willing to accept the CoV vaccine while 254 (35.28%) had no intention to take the vaccine [Table 1]. The median age of the subjects who were willing to accept CoV vaccines was 28 years (IQR = 18) while the median age of the subjects who were not willing to accept the CoV vaccines was 28 years (IQR = 17.75). A greater number of male (N = 245, 69.21%) and female (N = 221, 60.38%) participants intended to accept the CoV vaccine while only 109 male (30.79%) and 145 female (39.62%) participants did not intend to accept the CoV vaccine (P = 0.013). A statistically significant difference in vaccine acceptance was noticed among the respondents based on their area of residence (P = 0.000).
The 5C scale assessed the intention of the study participants to accept the CoV vaccine in five categories. The median and IQR were estimated for each question and each category [Table 2]. The median (IQR) values of confidence were 9.0 (2.0), complacency 5.0 (3.0), constraint 5.0 (4.0), calculation 9.0 (2.0), and collective responsibility 5.0 (1.25). The participants who were willing to accept the CoV vaccine expressed more confidence in the vaccines (9.0 [2.0]) compared to those who were not willing to accept (7.0 [3.0]) the vaccines (P < 0.001). Similarly, a significant difference in constraint (5.0 [4.0] vs. 5.0 [4.0]; P = 0.008) and calculation score (9.0 [2.0] vs. 9.0 [2.0]; P = 0.006) was observed among the subjects willing to accept the CoV vaccine compared with those who were not willing to accept the vaccines. The participants who showed reluctance toward vaccination were more complacent (6.0 [2.0]) than those who were willing to accept (5.0 [4.0]) the CoV vaccines (P < 0.001).
The source of information that participants preferred for updating their knowledge played a significant role in shaping their attitude. The participants who relied more on news media were less likely to accept the CoV vaccines (OR = 0.561, P = 0.009) compared to the reference of information accessed through government websites and portals. Similarly, the reliance on social media for information related to vaccines resulted in less likely to accept the CoV vaccines (OR = 0.574, P = 0.022). The participants who themselves got infected with CoV showed an approximately three times higher probability to accept the CoV vaccines (OR = 2.954, P = 0.010). The participants who expressed more confidence in vaccines (OR = 1.818, P < 0.001) and who took a calculated decision (OR = 1.183, P = 0.001) were more likely to accept CoV vaccines. On the other hand, the participants who were complacent (OR = 0.852, P = 0.000) and who took collective responsibility (OR = 0.891, P = 0.033) were less likely to accept CoV vaccines [Table 3].
|Table 3: Logistic regression to assess the effect of predictors on willingness to accept coronavirus vaccine|
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| Discussion|| |
The present study began during the latter part of the first phase of a vaccination drive against COVID-19 in India that was initiated for health-care workers and frontline workers. The importance of a vaccine in controlling an infectious disease depends upon the vaccine's efficacy and the willingness of the concerned population to accept it. In past research on different diseases, reasons for nonvaccination in India were related to awareness, acceptance, and affordability., If a large number of individuals refuse to receive a vaccine, the protection offered to the population is considerably diminished.
This study was among the earliest studies presenting the intention of the CoV vaccine among the general population of India. The estimates of willingness to get the CoV vaccine and its determinants have also been reported that may assist the primary care physicians in understanding the challenges and strategizing their role in building confidence toward CoV vaccines. In the past few months, there was a surge of interest in estimating the intention to be vaccinated against COVID-19 around the world., A recent survey of almost 20,000 adults in 27 countries showed that 74% of adults intended to receive CoV vaccine, with the highest rates in China (97%), Brazil (88%), Australia (88%), and India (87%) while the lowest in Russia (54%), Poland (56%), Hungary (56%), and France (59%)., The findings of this study were relatively lower compared with the other countries. In this survey of the Indian population, 64.72% of participants showed a willingness to accept the CoV vaccine coinciding exactly with 64% intended to be vaccinated in a study from the United Kingdom (UK). This was very similar to another study in the Irish and UK populations with 65% and 69% of respondents accepting the CoV vaccine., A small-scale study in the United States (US) reported a similar (67%) vaccination intent. However, some of the studies reported higher acceptance (79%–87%) of the CoV vaccine in the Indian population.,,,
Vaccination intention seems to be greater than the actual vaccine uptake. It is important to identify factors associated with vaccination intention, to support policy and communications. Given the importance of intention in theories of uptake of health behaviors, it is likely that factors associated with vaccination intention in this study will also influence vaccination uptake., Generally, men are more inclined to adopt pharmaceutical interventions and vaccination. The findings of this study also point out that men are more receptive to CoV vaccines similar to other studies., A review examining over 100 surveys capturing COVID-19 vaccine receptivity also agrees with this finding. A contrary relation, however weak, is found in a global survey where more females agreed to accept CoV vaccination.
Globally, scientists are committed to developing the vaccine against COVID-19 for children and adults; the unacceptability of the vaccine in the population can constitute one of the main hindrances for a future effective immunization against COVID-19. In this study, a significant number of the Indian population (35.28%) did not intend for vaccination, which is in line with the findings of a study in France. Those who were not accepting the CoV vaccine were more likely to be female which is a finding consistent with several US-based surveys and other studies identifying gender-related differences in vaccine acceptance.,
There is a significant difference in willingness to accept CoV vaccine among respondents of different areas of their residence. The reasons for this disparity may include limited access to primary care, failure to impart information on the importance of vaccination, their adverse effects and risks, and most importantly, the benefits of vaccination.
The psychological antecedents of vaccination predicted the intention to receive the CoV vaccine, as shown in studies on other vaccines., The statistical framework in this study suggested that the psychological constructs in the 5C model contributed in a significant way to explain the COVID-19 vaccination intention. While using the 5C scale in this study to analyze the psychological antecedents of CoV vaccines among the Indian population, instead of 7-point Likert format (e.g., 1 = totally agree and 7 = totally disagree) which may be a challenge for the participants, we have used 3-point Likert scale (1 = disagree, 2 = neutral, and 3 = agree) to reduce complexity and errors as advised in the original 5C protocol., It was also inferred that when there were more options, responses were more spread out which ultimately produced lower percentages of affirmative answers.
This survey is unique in bringing to light the fact that people of a younger age who perceived vaccines to be safe and effective (confidence) with perceived benefits (calculated decision) were associated with stronger willingness to be vaccinated against COVID-19 as found in an Indian and Malaysian survey. Therefore, any measures promoting information about the safety and effectiveness of vaccines should also aid in CoV vaccine acceptance. However, the belief that vaccines are unnecessary and other general anti-vaccine stands (complacency) along with collective responsibility were associated with lower acceptance in the 5C model similar in some studies but related to more acceptance in another study., However, this is contrary to a few studies where worries about side effects and the efficacy of the vaccine (confidence) have been reported as perceived barriers related to the introduction of a new vaccine.,
The respondents not willing to vaccinate, contrary to the vaccine accepting population, consumed significantly more information from social media and news media than from government websites and portals. This is very prominently expressed in other studies also., Contribution of social and news media as a source of information was significantly greater among people not intended to vaccinate. Previous infectious diseases such as H1N1, SARS, and Middle East Respiratory syndrome discovered that sources of information from government sources are fundamental to disease control. Therefore, systematic promotion of more reliable sources of information through government sites, official websites, and international organizations should be encouraged. The best strategy for encouraging vaccination against COVID-19 might be to find people who are not politically related, such as public health experts or prominent members of the community.
Interestingly, in this survey, participants who were infected with CoV showed three times higher probability to accept CoV vaccines, which is similar to another study. Similarly, a global survey in 19 countries with a high COVID burden showed no difference in vaccine acceptance among people who reported COVID-19 sickness in themselves and noninfected people.
To the best of our knowledge, this is among the earliest study investigating the intention to receive a CoV vaccination in a demographically representative sample of the Indian population. The willingness to vaccinate is lower than in other countries because the cases were on a declining trend in India during the time of data collection (February–March 2021) creating an intuitive that vaccine is no longer necessary. As vaccine uptake is likely to be lower than vaccination intention, the results from this study provide useful insights that can help to improve the vaccination uptake among the population. These findings reflect confidence among masses regarding vaccine effectiveness and safety. The belief that vaccination is a necessity and clear information about collective action of the vaccine to prevent the spread of the CoV may be needed to increase vaccination intentions.
This study provides several important public health implications in the identification of determinants associated with willingness to get COVID-19 vaccination that may help in future vaccination campaigns. However, there are certain limitations to this study. Firstly, a snowball sampling method was deployed that may have resulted in selection bias though the study obtained responses from 22 states and union territories of India and thus is representative of the general population. Secondly, being a web-based study, an intrinsic disadvantage remains that the participation could be limited to respondents with internet access and computer literacy along with those who understand the English language. This might be due to the intrinsic disadvantages of Web-based surveys as they concern the generality and validity of results warranting careful interpretation of the research findings. Thirdly, being a cross-sectional study, the participants were not followed up over time and the intention to receive CoV vaccine that varies over time with the variable rate of infection and mortality rate of the ongoing pandemic could not be studied. Fourthly, the outcomes were self-reported with a risk of source bias and recall bias. The findings of this survey need to be interpreted in light of the above-mentioned limitations. Despite these limitations, the findings contribute to understanding the psychological component of the Indian population regarding the COVID-19 vaccine. Hence, more emphasis needs to be placed on psychological components when implementing the nationwide vaccination program.
| Conclusion|| |
The results of this study provide valuable insights on public opinion of CoV vaccines, which can help enable policymakers and stakeholders to identify factors of particular concern for the surveyed areas of relevant psychological concepts, such as attitude (confidence), perceived personal health status and invulnerability (complacency), self-control (constraints), preference for deliberation (calculation), and communal orientation (collective responsibility). Demographic and socioeconomic factors influence the receptivity of CoV vaccines. Based on the factors for vaccine resistance, public health campaigns could be targeted at groups more likely to be vaccine-hesitant or resistant. Future studies can be planned to identify the characteristics of vaccine-hesitant or resistant sub-groups in different areas.
The authors would like to thank all the respondents who participated in this study. The contribution of all people who widely distributed Google Forms on social media is deeply acknowledged.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Jain J, Saurabh S, Kumar P, Verma MK, Goel AD, Gupta MK, et al.
COVID-19 vaccine hesitancy among medical students in India. Epidemiol Infect 2021;149:e132.
Lin C, Tu P, Beitsch LM. Confidence and receptivity for COVID-19 vaccines: A rapid systematic review. Vaccines (Basel) 2020;9:16.
Bhartiya S, Kumar N, Singh T, Murugan S, Rajavel S, Wadhwani M. Knowledge, attitude and practice towards COVID-19 vaccination acceptance in West India. Int J Community Med Public Health 2021;8:1170-76.
Moberly T. Covid-19: Vaccine hesitancy fell after vaccination programme started. BMJ 2021;372:n837.
Murphy J, Vallières F, Bentall RP, Shevlin M, McBride O, Hartman TK, et al.
Psychological characteristics associated with COVID-19 vaccine hesitancy and resistance in Ireland and the United Kingdom. Nat Commun 2021;12:29.
Chakraborty C, Sharma AR, Bhattacharya M, Agoramoorthy G, Lee SS. Asian-origin approved COVID-19 vaccines and current status of COVID-19 vaccination program in Asia: A critical analysis. Vaccines (Basel) 2021;9:600.
Eysenbach G. Improving the quality of Web surveys: The Checklist for Reporting Results of Internet E-Surveys (CHERRIES). J Med Internet Res 2004;6:e34.
Betsch C, Schmid P, Heinemeier D, Korn L, Holtmann C, Böhm R. Beyond confidence: Development of a measure assessing the 5C psychological antecedents of vaccination. PLoS One 2018;13:e0208601.
Betsch C, Habersaat KB, Deshevoi S, Heinemeier D, Briko N, Kostenko N, et al
. Sample study protocol for adapting and translating the 5C scale to assess the psychological antecedents of vaccination. BMJ Open 2020;10:e034869.
Nagar R, Venkat P, Stone LD, Engel KA, Sadda P, Shahnawaz M. A cluster randomized trial to determine the effectiveness of a novel, digital pendant and voice reminder platform on increasing infant immunization adherence in rural Udaipur, India. Vaccine 2018;36:6567-77.
Francis MR, Nohynek H, Larson H, Balraj V, Mohan VR, Kang G, et al.
Factors associated with routine childhood vaccine uptake and reasons for non-vaccination in India: 1998-2008. Vaccine 2018;36:6559-66.
Bokemper SE, Huber GA, Gerber AS, James EK, Omer SB. Timing of COVID-19 vaccine approval and endorsement by public figures. Vaccine 2021;39:825-9.
Detoc M, Bruel S, Frappe P, Tardy B, Botelho-Nevers E, Gagneux-Brunon A. Intention to participate in a COVID-19 vaccine clinical trial and to get vaccinated against COVID-19 in France during the pandemic. Vaccine 2020;38:7002-6.
Graffigna G, Palamenghi L, Boccia S, Barello S. Relationship between Citizens' Health engagement and intention to take the COVID-19 vaccine in Italy: A mediation analysis. Vaccines (Basel) 2020;8:576.
Sherman SM, Smith LE, Sim J, Amlôt R, Cutts M, Dasch H, et al.
COVID-19 vaccination intention in the UK: Results from the COVID-19 vaccination acceptability study (CoVAccS), a nationally representative cross-sectional survey. Hum Vaccin Immunother 2021;17:1612-21.
Pogue K, Jensen JL, Stancil CK, Ferguson DG, Hughes SJ, Mello EJ, et al.
Influences on attitudes regarding potential COVID-19 vaccination in the United States. Vaccines (Basel) 2020;8:582.
Malik AA, McFadden SM, Elharake J, Omer SB. Determinants of COVID-19 vaccine acceptance in the US. EClinicalMedicine 2020;26:100495.
Kumari A, Ranjan P, Chopra S, Kaur D, Kaur T, Upadhyay AD, et al.
Knowledge, barriers and facilitators regarding COVID-19 vaccine and vaccination programme among the general population: A cross-sectional survey from one thousand two hundred and forty-nine participants. Diabetes Metab Syndr 2021;15:987-92.
Jacob J, Stephen S, Issac A, Krishnan N, Radhakrishnan RV, Vijay VR, et al
. Determinants of willingness for COVID-19 vaccine: Implications for Enhancing the Proportion of Vaccination Among Indians. Cureus 2021;13:e15271.
Sniehotta FF, Scholz U, Schwarzer R. Bridging the intention-behaviour gap: Planning, self-efficacy, and action control in the adoption and maintenance of physical exercise. Psychol Health 2005;20:143-60.
Ajzen I. The theory of planned behavior. Organ Behav Hum Decis Process 1991;50:179-211.
Moran KR, Del Valle SY. A meta-analysis of the association between gender and protective behaviors in response to respiratory epidemics and pandemics. PLoS One 2016;11:e0164541.
Dror AA, Eisenbach N, Taiber S, Morozov NG, Mizrachi M, Zigron A, et al.
Vaccine hesitancy: The next challenge in the fight against COVID-19. Eur J Epidemiol 2020;35:775-9.
Lazarus JV, Ratzan SC, Palayew A, Gostin LO, Larson HJ, Rabin K, et al.
A global survey of potential acceptance of a COVID-19 vaccine. Nat Med 2021;27:225-8.
Pulcini C, Massin S, Launay O, Verger P. Factors associated with vaccination for hepatitis B, pertussis, seasonal and pandemic influenza among French general practitioners: A 2010 survey. Vaccine 2013;31:3943-9.
Neufeind J, Betsch C, Habersaat KB, Eckardt M, Schmid P, Wichmann O. Barriers and drivers to adult vaccination among family physicians – Insights for tailoring the immunization program in Germany. Vaccine 2020;38:4252-62.
Wallace AS, Wannemuehler K, Bonsu G, Wardle M, Nyaku M, Amponsah-Achiano K, et al.
Development of a valid and reliable scale to assess parents' beliefs and attitudes about childhood vaccines and their association with vaccination uptake and delay in Ghana. Vaccine 2019;37:848-56.
Schmid P, Rauber D, Betsch C, Lidolt G, Denker ML. Barriers of influenza vaccination intention and behavior – A systematic review of influenza vaccine hesitancy, 2005 – 2016. PLoS One 2017;12:e0170550.
Siegrist M, Zingg A. The role of public trust during pandemics: Implications for crisis communication. Eur Psychol 2014;19:23-32.
[Table 1], [Table 2], [Table 3]