A Prediction Model for Identifying Seasonal Influenza Vaccination Uptake Among Children in Wuxi, China: Prospective Observational Study.

BACKGROUND: Predicting vaccination behaviors accurately could provide insights for health care professionals to develop targeted interventions. OBJECTIVE: The aim of this study was to develop predictive models for influenza vaccination behavior among children in China. METHODS: We obtained data from a prospective observational study in Wuxi, eastern China. The predicted outcome was individual-level vaccine uptake and covariates included sociodemographics of the child and parent, parental vaccine hesitancy, perceptions of convenience to the clinic, satisfaction with clinic services, and willingness to vaccinate. Bayesian networks, logistic regression, least absolute shrinkage and selection operator (LASSO) regression, support vector machine (SVM), naive Bayes (NB), random forest (RF), and decision tree classifiers were used to construct prediction models. Various performance metrics, including area under the receiver operating characteristic curve (AUC), were used to evaluate the predictive performance of the different models. Receiver operating characteristic curves and calibration plots were used to assess model performance. RESULTS: A total of 2383 participants were included in the study; 83.2% of these children (n=1982) were <5 years old and 6.6% (n=158) had previously received an influenza vaccine. More than half (1356/2383, 56.9%) the parents indicated a willingness to vaccinate their child against influenza. Among the 2383 children, 26.3% (n=627) received influenza vaccination during the 2020-2021 season. Within the training set, the RF model showed the best performance across all metrics. In the validation set, the logistic regression model and NB model had the highest AUC values; the SVM model had the highest precision; the NB model had the highest recall; and the logistic regression model had the highest accuracy, F1 score, and Cohen κ value. The LASSO and logistic regression models were well-calibrated. CONCLUSIONS: The developed prediction model can be used to quantify the uptake of seasonal influenza vaccination for children in China. The stepwise logistic regression model may be better suited for prediction purposes.

Perceptions about respiratory syncytial virus (RSV) and attitudes toward the RSV vaccine among the general public in China: A cross-sectional survey.

Our study aims to assess the public's perceptions of respiratory syncytial virus (RSV) and attitudes toward the RSV vaccine and to identify associated factors in China. A nationwide cross-sectional survey conducted using an online platform between August 16 and September 14, 2023. Questions related to socio-demographics, awareness, knowledge, perceptions of susceptibility and severity of RSV, and attitudes toward the RSV vaccine were included in the questionnaire. We used the chi-square test and logistic regression model to explore the associated factors. Overall, 2133 individuals were included in this study. Nearly a quarter of participants (24.3%) indicated that they had never heard of RSV. The proportion of individuals aged over 50 years reporting never having heard of RSV (36.5%) and having a low knowledge level of RSV (55.3%) was significantly higher that of other younger age groups. More than half of individuals (55.7%) exhibited low level of perceptions of susceptibility concerning RSV infection. A total of 68.4% of the participants expressed willingness to receive the RSV vaccine. Younger age was positively associated with a higher willingness to be vaccinated. The most frequent reason for declining the vaccine was "Concern about vaccine's safety or side effects." About 60% of individuals considered a price of RSV vaccine below 200 CNY (28 USD) as acceptable. The awareness and perceived susceptibility to RSV infection were limited to the Chinese public. It is necessary to take measures to address the low awareness and knowledge of RSV and acceptability of the RSV vaccine among older adults.

Impact of implementing a free varicella vaccination policy on incidence in Wuxi City, China: an interrupted time series analysis.

Varicella vaccination is optional and requires self-payment. On 1 December 2018, Wuxi City launched a free varicella vaccination program for children. This study aimed to evaluate the changes in varicella incidence before and after the implementation of the policy. The data were obtained from official information systems and statistical yearbooks. We divided the period into chargeable (January 2017 to November 2018) and free (December 2018 to December 2021) periods. Interrupt time series analysis was used to conduct a generalised least-squares regression analysis for the two periods. A total of 51,071 varicella cases were reported between January 2017 and December 2021. After the implementation of the policy, there was a statistically significant decrease in the incidence of varicella (ß2 = -0.140, P = 0.017), and the slope of the incidence also decreased by 0.012 (P = 0.015). Following policy implementation, the incidence decreased in all age groups, with the largest decline observed among children aged 8-14 years (ß2 = -1.109, P = 0.009), followed by children aged ≤7 years (ß2 = -0.894, P = 0.013). Our study found a significant reduction in the incidence of varicella in the total population after the introduction of free varicella vaccination in Wuxi City.

Perceptions and acceptability of HPV vaccination among parents of female adolescents 9-14 in China: A cross-sectional survey based on the theory of planned behavior.

HPV vaccine uptake remains low in China, especially among girls. Recently, China has initiated a pilot program on HPV immunization for girls 9-14. From November to December 2021, a cross-sectional study was conducted among parents of girls 9-14 in China through a web-based anonymous online questionnaire survey. Descriptive epidemiological analysis was used to analyze parental acceptability. Hierarchical regression analysis and structural equation modeling were to determine associated factors. A total of 5623 participants were included in the analysis. 21.2% girls had received HPV vaccine, and 94.3% parents intended to receive vaccination for their daughters, the Kappa values between them was -0.016. 31.9% of vaccinated mothers had received HPV vaccine for their daughters, vaccination history had a positive impact on behavior (ß = 0.048). Attitude (ß = 0.186), subjective norms (ß = 0.148) and perceived behavioral control (ß = 0.648) had a positive impact on intention. Vaccination intention mediated the relationships between attitude (ß = 0.044), subjective norms (ß = 0.035), and perceived behavioral control (ß = 0.154) with behavior. There is a gap between vaccination intention and behavior in parents of girls 9-14. Perceived behavior control had a strong association on HPV vaccination behavior.

Assessing vaccine literacy and exploring its association with vaccine hesitancy: A validation of the vaccine literacy scale in China.

BACKGROUND: Assessment of vaccine literacy is essential for understanding people's ability to access various vaccine information to meet health demands. Few studies have examined the role of vaccine literacy in vaccine hesitancy, which is a psychological state. This study aimed to validate the applicability of the HLVa-IT (Vaccine Health Literacy of Adults in Italian) scale in Chinese settings and to explore the association between vaccine literacy and vaccine hesitancy. METHODS: From May to June 2022, we conducted an online cross-sectional survey in mainland China. Potential factor domains were obtained by the exploratory factor analysis. Cronbach's alpha coefficient, composite reliability values, and square root values of average variances extracted were calculated to determine the internal consistency and discriminant validity. The association between vaccine literacy, vaccine acceptance, with vaccine hesitancy was assessed using logistic regression analysis. RESULTS: Totally, 12,586 participants completed the survey. Two potential dimensions, the functional and the interactive/critical, were identified. Cronbach's alpha coefficient and composite reliability values were >0.90. The square root values of average variances extracted exceeded the related correlations. The functional dimension (adjusted odds ratio (aOR): 0579; 95 % Confidence Interval (CI); 0.529, 0.635), interactive (aOR: 0.654; 95%CI: 0.531, 0.806)/critical (aOR: 0.709; 95%CI: 0.575, 0.873) dimension were significantly and negatively associated with vaccine hesitancy. Similar results were also found in different vaccines acceptance subgroups. LIMITATIONS: This report is limited by the convenience sampling method. CONCLUSIONS: The modified HLVa-IT is suitable for use in Chinese settings. Vaccine literacy was negatively associated with vaccine hesitancy.

Understanding Drivers of Vaccine Hesitancy During the COVID-19 Pandemic Among Older Adults in Jiangsu Province, China: Cross-sectional Survey.

BACKGROUND: Older adults are particularly at risk from infectious diseases, including serve complications, hospitalization, and death. OBJECTIVE: This study aimed to explore the drivers of vaccine hesitancy among older adults based on the "3Cs" (confidence, complacency, and convenience) framework, where socioeconomic status and vaccination history played the role of moderators. METHODS: A cross-sectional questionnaire survey was conducted in Jiangsu Province, China, between June 1 and July 20, 2021. Older adults (aged ≥60 years) were recruited using a stratified sampling method. Vaccine hesitancy was influenced by the 3Cs in the model. Socioeconomic status and vaccination history processed through the item parceling method were used to moderate associations between the 3Cs and hesitancy. Hierarchical regression analyses and structural equation modeling were used to test the validity of the new framework. We performed 5000 trials of bootstrapping to calculate the 95% CI of the pathway's coefficients. RESULTS: A total of 1341 older adults participated. The mean age was 71.3 (SD 5.4) years, and 44.7% (599/1341) of participants were men. Confidence (b=0.967; 95% CI 0.759-1.201; P=.002), convenience (b=0.458; 95% CI 0.333-0.590; P=.002), and less complacency (b=0.301; 95% CI 0.187-0.408; P=.002) were positively associated with less vaccine hesitancy. Socioeconomic status weakened the positive effect of low complacency (b=-0.065; P=.03) on low vaccine hesitancy. COVID-19 vaccination history negatively moderated the positive association between confidence (b=-0.071; P=.02) and lower vaccine hesitancy. CONCLUSIONS: Our study identified that confidence was the more influential dimension in reducing vaccine hesitancy among older adults. COVID-19 vaccination history, as well as confidence, had a positive association with less vaccine hesitancy and could weaken the role of confidence in vaccine hesitancy. Socioeconomic status had a substitution relationship with less complacency, which suggested a competitive positive association between them on less vaccine hesitancy.

Understanding drivers of influenza vaccine hesitancy among pregnant women in China: evidence from an extended theory of planned behavior.

BACKGROUND: Pregnant women's influenza vaccination uptake was low, although being recommended as a priority. RESEARCH DESIGN AND METHODS: We conducted a cross-sectional questionnaire survey in China from June to July 2021. Hierarchical regression analysis and structural equation modeling were performed based on the extended theory of planned behavior, in which attitudes, subjective norms, perceived behavioral control, and intention each affect vaccine hesitancy; response efficacy, knowledge, vulnerability, and severity were added as extended dimensions; vaccination history played as a moderator. RESULTS: Totally, 1283 pregnant women participated in this study. The intention existed as a mediator between attitude [ßindirect = 0.142 (95% confidence interval (CI): 0.084, 0.206), P < 0.001], subjective norms [ßindirect = 0.568 (95%CI: 0.424, 0.754), P < 0.001], perceived behavioral control [ßindirect = 0.070 (95%CI: 0.025, 0.118), P = 0.004] and vaccine hesitancy. Further, indirect effect differences between the two dimensions of attitude (P < 0.001), perceived behavioral control (P < 0.001), and subjective norms were each statistically significant. Vaccination history did not moderate the association between attitude (P = 0.679), subjective norms (P = 0.645), and hesitancy. CONCLUSIONS: The subjective norms dimension has a strong association with influenza vaccine hesitancy. Vaccination history was limited to reduce hesitancy.

Vaccination Intention and Behavior of the General Public in China: Cross-sectional Survey and Moderated Mediation Model Analysis.

BACKGROUND: Promoting vaccination and eliminating vaccine hesitancy are key measures for controlling vaccine-preventable diseases. OBJECTIVE: We aimed to understand the beliefs surrounding and drivers of vaccination behavior, and their relationships with and influence on vaccination intention and practices. METHODS: We conducted a web-based survey in 31 provinces in mainland China from May 24, 2021 to June 15, 2021, with questions pertaining to vaccination in 5 dimensions: attitude, subjective norms, perceived behavioral control, intention, and behavior. We performed hierarchical regression analysis and structural equation modeling based on the theory of planned behavior-in which, the variables attitude, subjective norms, and intention each affect the variable intention; the variable intention mediates the relationships of attitude and subjective norms with behavior, and the variable perceived behavioral control moderates the strength of this mediation-to test the validity of the theoretical framework. RESULTS: A total of 9924 participants, aged 18 to 59 years, were included in this study. Vaccination intention mediated the relationships of attitude and subjective norms with vaccination behavior. The indirect effect of attitude on vaccination behavior was 0.164 and that of subjective norms was 0.255, and the difference was statistically significant (P<.001). The moderated mediation analysis further indicated that perceived behavioral control would affect the mediation when used as moderator, and the interaction terms for attitude (ß=-0.052, P<.001) and subjective norms (ß=-0.028, P=.006) with perceived behavioral control were significant. CONCLUSIONS: Subjective norms have stronger positive influences on vaccination practices than attitudes. Perceived behavioral control, as a moderator, has a substitution relationship with attitudes and subjective norms and weakens their positive effects on vaccination behavior.

Changes in Parental Attitudes Toward COVID-19 Vaccination and Routine Childhood Vaccination During the COVID-19 Pandemic: Repeated Cross-sectional Survey Study.

BACKGROUND: It was reported that one in four parents were hesitant about vaccinating their children in China. Previous studies have revealed a declining trend in the vaccine willingness rate in China. There is a need to monitor the level of parental vaccine hesitancy toward routine childhood vaccination and hesitancy toward the COVID-19 vaccine during the ongoing COVID-19 pandemic. OBJECTIVE: This study aims to assess changes in trends of parental attitudes toward routine childhood vaccines and COVID-19 vaccinations across different time periods in China. METHODS: Three waves of cross-sectional surveys were conducted on parents residing in Wuxi City in Jiangsu Province, China from September to October 2020, February to March 2021, and May to June 2021. Participants were recruited from immunization clinics. Chi-square tests were used to compare the results of the three surveys, controlling for sociodemographic factors. Binary and multivariable logistic regression analysis was used to examine factors related to parental vaccine hesitancy and COVID-19 vaccine willingness. RESULTS: Overall, 2881, 1038, and 1183 participants were included in the survey's three waves. Using the Vaccine Hesitancy Scale, 7.8% (225/2881), 15.1% (157/1038), and 5.5% (65/1183) of parents showed hesitancy to childhood vaccination (P<.001), and 59.3% (1709/2881), 64.6% (671/1038), and 92% (1088/1183) of parents agreed to receive a COVID-19 vaccine themselves in the first, second, and third surveys, respectively (P<.001). In all three surveys, "concerns about vaccine safety and side effects" was the most common reason for refusal. CONCLUSIONS: There has been an increasing acceptance of COVID-19 vaccination in Wuxi City, China. Effective interventions are needed to mitigate public concerns about vaccine safety.

Validation of the World Health Organization's parental vaccine hesitancy scale in China using child vaccination data.

Evidence for the validity and reliability of the World Health Organization's 10-item vaccine hesitancy scale (VHS) in different settings is not sufficient, especially for criteria validity. This study aimed to assess the validity and reliability of the VHS using child vaccination data in China. A cross-sectional survey was performed with parents of 19-48-month-old children at six vaccination clinics in Wuxi City between September and October 2020. The VHS was revised to category A (expanded program on immunization, EPI) VHS and category B (Non-EPI) VHS. Factor analysis was used to confirm the latent domain and to assess the model structure. The average variance extracted (AVE) was calculated to assess convergent validity, and Cronbach's α and composite reliability (CR) were used to determine internal consistency. The association between VHS scores and children's vaccination status was examined to assess criteria validity using logistic regression. The survey response rate was 75.3% (n = 802). Two factors were identified, explaining 64.60% and 63.34% of the common variance in categories A and B VHS, respectively. The Cronbach's α of > 0.7 and CR of >0.7 in the scale indicated the VHS has acceptable internal consistency. The AVE values indicated that convergent validity was not ideal for the VHS. There were no statistically significant associations between VHS scores and vaccination status, indicating that the criterion validity was not ideal. The VHS needs improvement before becoming a standard survey tool.

Parental category B vaccine hesitancy and associated factors in China: an online cross-sectional survey.

BACKGROUND: Vaccine hesitancy is one of the top ten health threats. We aimed to (1) assess parental Category B vaccines hesitancy and associated sociodemographic factors in China, and (2) explore the association between attitude toward vaccines and self-reported hesitant behavior. METHODS: A cross-sectional study was performed through a web-based anonymous online questionnaire survey between 9 February and 7 April 2021. Chinese parents aged ≥ 18 years with one child aged < 6 years were included to assess vaccine hesitancy using the vaccine-hesitancy scale (VHS). Structural equation model was used to determine relationships between variables. RESULTS: Of 2952 Chinese parents included in the analysis, 17.5% were highly hesitant in Category B vaccines. Parents who were younger, less educated, engaged in health-related occupations, and had been vaccinated against influenza in the past year were more hesitant when vaccinating their children (P < 0.001). VHS score accuracy to identify vaccine-hesitant behavior was acceptable, and the optimal cutoff was 37.50 (with 61.96% parental vaccine hesitancy). Parents who lack confidence or believe vaccines were risk were more likely to show vaccine hesitant behavior (P < 0.001). CONCLUSIONS: In China, effective interventions need to be implemented to eliminate parental Category B vaccines hesitancy.

Delays in routine childhood vaccinations and their relationship with parental vaccine hesitancy: a cross-sectional study in Wuxi, China.

OBJECTIVES: This study aimed to examine childhood vaccination delay, explore the association between vaccination delay and parental vaccine hesitancy, and assess childhood vaccination delays during the coronavirus disease (COVID)-19 pandemic in China. METHODS: This cross-sectional survey was conducted in Wuxi City. Participants were recruited from local vaccination clinics. Questionnaires were used to collect information about socio-demographics, vaccine hesitancy, and immunization clinic evaluations. Vaccination records were obtained from the Jiangsu Information Management System of Vaccination Cases. RESULTS: Overall, 2728 participants were included. The coverage for seven category A vaccines (Expanded Program on Immunization (EPI)) was more than 95% at 24 months. The proportion of children vaccinated in a timely manner was the highest for the first dose of the hepatitis B vaccine (91.6%) and the lowest for the Bacillus-Calmette-Guerin vaccine (44.6%). More than 50% of the planned vaccinations were delayed in February and March 2020. The Vaccine Hesitancy Scale scores were not associated with vaccination delay (P = 0.842). Children's vaccination delays were negatively associated with parents who reported convenient access to clinics and satisfaction with immunization services (P = 0.020, P = 0.045). CONCLUSIONS: EPI is highly successful in China. Despite vaccination delays due to the COVID-19 pandemic, coverage was recovered after lockdown restrictions were eased.

Economic evaluation of varicella vaccination strategies in Jiangsu province, China: a decision-tree Markov model.

This study evaluated different varicella vaccination strategies in Jiangsu province, China. A decision-tree Markov model was used to evaluate the cost effectiveness of various varicella vaccination strategies for children, including direct and selective vaccination (serotesting pre-vaccination). A cohort of one-year-old children was followed through 60 one-year Markov cycles. The parameter estimation was based on field work, the literature, and statistical yearbooks. We calculated the incremental cost-utility ratio (ICUR) using the saved quality-adjusted life year (QALY). One-way and probability sensitivity analyses were performed to assess uncertainty. Among 100,000 cohort members, one-dose and two-dose direct vaccination averted 8061 and 10,701 varicella cases, respectively, compared with no vaccination. Furthermore, compared with no vaccination, one-dose and two-dose direct vaccination saved one QALY at the ICUR of USD 21,401.33 and USD 35,420.81, respectively, at less than three times the per capita gross domestic product (USD 47,626.86) of Jiangsu. The ICURs of the one-dose and two-dose selective strategies versus no vaccination were USD 42,623.62 and USD 51,406.35 per QALY gained, respectively. The cost effectiveness results were most sensitive to the QALY loss of outpatients and vaccine prices. Thus, in Jiangsu, one-dose and two-dose direct varicella vaccination in children could be cost effective at the willingness to pay threshold of three times provincial GDP per capita from a societal perspective. The findings were sensitive to the vaccine price and health utility of varicella cases.

Non-EPI Vaccine Hesitancy among Chinese Adults: A Cross-Sectional Study.

Vaccination against coronavirus disease 2019 (COVID-19) is paramount to curtailing the pandemic. However, the impact of the Non-Expanded Program on Immunization (non-EPI) and COVID-19 vaccine hesitancy on vaccine uptake among Chinese adults remain unclear. This study was an online survey performed in Eastern, Central, and Western China between February 2021 and March 2021 using proportional sampling (n = 7381). Adults aged ≥ 18 years were included, especially younger people (aged < 65). Vaccine hesitancy was assessed using the 3C model and relative scales; logistic regression was used to explore the factors affecting vaccination uptake; structural equation modeling was used to evaluate the correlations between variables. Overall, 67.6% and 24.7% of adults reported vaccine hesitancy toward the non-EPI and COVID-19 vaccines, respectively. Participants (66.3%) reported taking the vaccine mainly based on recommendations from medical staff. Vaccine-hesitant participants (60.5%) reported a fear of side effects as the deciding factor in vaccine rejection. Vaccine hesitancy interacted negatively with confidence (ß = -0.349, p < 0.001) and convenience (ß = -0.232, p < 0.001), and positively with complacence (ß = 0.838, p < 0.001). Nonmedical personnel, adults who had previously received the influenza vaccine, and older people had lower vaccine hesitancy than their counterparts. Most Chinese adults have non-EPI but not COVID-19 vaccine hesitancy. Vaccine safety remains a concern.

Vaccine Hesitancy: COVID-19 and Influenza Vaccine Willingness among Parents in Wuxi, China-A Cross-Sectional Study.

OBJECTIVES: We aimed to (1) assess parental hesitancy about category A (Expanded Program on Immunization (EPI)) and B (non-EPI) vaccines, (2) assess parental willingness for COVID-19 and influenza vaccinations, and (3) explore the association of vaccination hesitancy of parents and healthcare workers (HCWs). METHODS: The study was performed in Wuxi, eastern China between 21 September 2020 and 17 October 2020. Parents of children aged <18 years and HCWs were recruited from the selected immunization clinics. Vaccine hesitancy was assessed using the Strategic Advisory Group of Experts (SAGE) vaccine hesitancy survey (VHS) by summing the total score for 10 items (maximum 50 points). RESULTS: A total of 3009 parents and 86 HCWs were included in the analysis. The category A VHS scores were significantly higher than the category B VHS scores (p = 0.000). Overall, 59.3% and 52.4% of parents reported willingness to avail COVID-19 and influenza vaccination for their children, respectively; 51.2% of the HCWs wanted to be vaccinated against COVID-19. Parental category B VHS scores were associated with HCW category B VHS scores (r = 0.928, p = 0.008). CONCLUSIONS: In China, parents are more hesitant about category B vaccines than category A vaccines. More than 40% of parents showed hesitancy and a refusal to use COVID-19 and influenza vaccines.