Changes in parents’ decisions pertaining to vaccination of their children after the Changchun Changsheng vaccine scandal in Guangzhou, China

Bibliometric and visual analyses of vaccine literacy research from 1982 to 2023

Vaccine literacy (VL) is an important part of health literacy (HL), which is of great significance in reducing vaccine hesitancy and improving vaccine coverage rate. We aimed to perform a bibliometric analysis of VL research conducted from 1982 to 2023 to evaluate its current status and prospects. All relevant publications were retrieved from the Web of Science Core Collection database and the Scopus database. The Bibliometrix R-package and VOSviewer software were used to analyze the publication outputs, countries, organizations, authors, journals, cited publications, and keywords. In total, 1,612 publications were included. The number of articles published on VL generally showed an increasing trend. The United States was in a leading position among all countries and had the closest connections with other countries and organizations. Its in-depth study of vaccine hesitancy provided a good foundation for VL research. Harvard University was the most productive organization. Bonaccorsi G was the most productive and cited author. VACCINES was the most productive journal. Research topics primarily revolved around vaccination, HL, vaccine hesitancy, and COVID-19 vaccine. In conclusion, the current research on the conceptual connotation and influencing factors of VL is insufficiently deep and should be further improved in the future to distinguish it from HL in a deeper manner. More tools for measuring VL need to be developed, such as those applicable to different populations and vaccines. The more complex relationship between VL, vaccine hesitancy and vaccination needs to be further explored. Gender differences deserve further investigation.

Can social media promote vaccination? Strategies and effectiveness of COVID-19 vaccine popularization on Chinese Weibo

Background

The COVID-19 pandemic has shown a high severity in terms of mortality, and to mitigate the impact of the COVID-19 pandemic, a great deal of reliance has been placed on vaccines with defensive effects. In the context of the transmission of hazardous Omicron variant strains, vaccine popularization and acceptance are very important to ensure world health security. Social media can spread information and increase public confidence in and acceptance of vaccines.

Method

In this study, weibos related to "vaccine science popularization" during the COVID-19 pandemic in China were collected, and Weibo publishers were divided into Individuals, Organizations, Media, Government, and Scientists. The communication strategies were analyzed with content analysis from the four dimensions of Issue, Topic, Frame, and Position. SnowNLP was used to mine the audience comments and to assess their emotional tendencies. Finally, hierarchical regression was used to verify the causal relationship between vaccine science popularization strategies and audiences' emotions.

Results

We found that the higher the scientific authority of the weibo publisher, the more positive the emotional tendency of the audience toward the weibo. Issues that are scientific, authoritative, and positive topics that positively present the advantages of the COVID-19 vaccine, and frames with detailed narratives, scientific arguments, diversified forms of presentations, and positions in support of the COVID-19 vaccine, positively affect the effect of vaccine popularization.

Discussion

Based on the experience of COVID-19 vaccine promotion in China, the results may serve as a reference for promoting innovative vaccines and handling public health affairs around the world.

Seroprevalence of Diphtheria and Tetanus Immunoglobulin G among the General Health Population in Guangzhou, China

A seroepidemiological study was conducted in 2018 to assess diphtheria and tetanus antibodies in Guangzhou, China. Diphtheria and tetanus antibody concentrations were measured with an enzyme-linked immunosorbent assay. A total of 715 subjects were enrolled in the study. The overall diphtheria and tetanus toxoid IgG-specific antibody levels were 0.126 IU/mL (95% CI: 0.115, 0.137) and 0.210 IU/mL (95% CI: 0.185, 0.240), respectively; the overall positivity rate was 61.82% (95% CI: 58.14, 65.39) and 71.61% (95% CI: 68.3, 74.92), respectively. The diphtheria and tetanus antibody concentration was decreased by age and increased by doses. The geometric mean concentrations and positivity rate of diphtheria and tetanus antibodies were lowest and below the essential protection level in people over 14 years of age. Compared to children and adolescents, middle-aged people and the aged are at much higher risk of infection with Corynebacterium diphtheriae and Clostridium tetani. The current diphtheria and tetanus immunization schedule does not provide persistent protection after childhood. There is an urgent need to adjust the current immunization schedule.

Assessing the impact of the 2018 Changchun Changsheng vaccine incident on childhood vaccination in China

BACKGROUND

The 2018 Changchun Changsheng vaccine incident is an emergent public health event in China with reports of DTaP vaccines with compromised efficacy. This study aimed to estimate the impact of the vaccine incident on real-world vaccination behaviors in China.

METHODS

A cross-sectional survey was conducted in ten provinces in 2019. Vaccination records were collected from 5294 children aged 6-59 months, with information on 75,579 vaccine doses for seven National Immunization Program (NIP) vaccines and two non-NIP vaccines received from 2014 to 2019. Chi-square test, interrupted time series, and logistic regression were used to evaluate the impacts of vaccine incident on vaccination delay, measured as the proportion of delayed doses out of total doses in schedule.

RESULTS

Here we show significant increases in doses delayed ≤ 3 months (19.12% to 22.51%, p = 0.000) and > 3 months (7.17% to 11.82%, p = 0.000) for DTaP vaccine after the incident. By scaling nationally, there will be extra 2.1 million doses delayed ≤ 3 months and 2.8 million doses delayed > 3 months in the year following this incident. More guardians choose expensive private-market substitutes containing DTaP elements over government-funded DTaP vaccines. Controlling for socio-demographic factors, doses scheduled after the incident have higher odds of delays for DTaP vaccine (OR: 3.49, 95% CI: 3.08-3.96) and other NIP vaccines (OR: 2.76, 95% CI: 2.55-2.99), but not for non-NIP vaccines.

CONCLUSIONS

The observed delays in the incident-involved DTaP vaccine immunization reflect the negative effects of the vaccine incident on vaccination behaviors under the NIP. However, its effects seem minimal for non-NIP vaccines.

Reliability and validity evaluation of the chinese revision of the attitude towards adult vaccination scale

BACKGROUND

Although vaccination is one of the critical interventions to address global health issues, inadequate vaccination rates has become an international challenge. Vaccine hesitancy is the key to affecting inadequate vaccination rates. According to the WHO SAGE working group's definition, vaccine hesitancy refers to delaying or refusing vaccination and has been ranked as one of the top 10 health threats. There has yet to be a scale that evaluates vaccination attitudes among Chinese adults. However, an attitude quantity, the adult vaccination attitude scale, has been developed to assess adult vaccination attitudes and reasons for vaccine hesitancy.

OBJECTIVE

The Adult Attitudes to Vaccination Scale (ATAVAC) was initially developed by Professor Zoi Tsimtsiou et al. This study aimed to analyze the structure of the Chinese version of the ATAVAC and explore the relationship between adult vaccination attitudes, e-health literacy, and medical distrust.

METHODS

After obtaining author permission for the initial scales, the study was translated using the Brislin back-translation method. 693 adults were enrolled to the study. To validate this hypothesis, participants finished the socio-demographic questionnaire, the Chinese version of the ATAVAC, the electronic Health Literacy Scale (e-HEALS) and the Medical Mistrust Index (MMI). The exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) were used to examine the underlying structure of the factors of the Chinese version of the Adult Vaccination Attitude Scale and to measure its reliability and validity.

RESULTS

The Cronbach's alpha coefficient for the Chinese version of the ATAVAC was 0.885, with Cronbach's alpha coefficients ranging from 0.850 to 0.958 for each dimension. The content validity index was 0.90, and the retest reliability was 0.943. The exploratory factor analysis (EFA) supported the 3-factor structure of the translation instrument, and the scale had good discriminant validity. The confirmatory factor analysis (CFA) revealed a degree of freedom of 1.219, a model fit index (GFI) of 0.979, a normative fit index (NFI) of 0.991, a Tucker-Lewis index (TLI) of 0.998, a comparability index (CFI) of 0.998 and a root mean square error of approximation (RMSEA) of 0.026.

CONCLUSION

The results show that the Chinese version of the ATAVAC has demonstrated good reliability and validity. Hence, it can be used as an effective tool to assess vaccination attitudes among Chinese adults.

Assessing vaccine hesitancy using the WHO scale for caregivers of children under 3 years old in China

Introduction

Vaccine hesitancy may increase infectious disease burden and impede disease control efforts, while few studies have measured such a phenomenon with a standardized tool in China. This study aimed to test the validation of the Vaccine Hesitancy Scale (VHS) developed by the WHO SAGE Working Group among caregivers and examine demographic characteristics associated with caregiver hesitancy in six provinces of China.

Methods

Using a multistage sampling design, this study was conducted in 36 immunization clinics in six provinces from December 2019 to August 2020. Caregivers of children aged 0-3  years were included. The VHS was used to assess vaccine hesitancy. The construct validity and internal consistency of the scale were assessed. Associations between caregivers' characteristics and vaccine hesitancy were examined by simple and multiple linear regression models.

Results

Of the 3,359 participants included, a two-factor structure within the scale was identified, consisting of "lack of confidence" (1.89 ± 0.53) and "risks" (3.20 ± 0.75). Caregivers engaged in medical work expressed more confidence and were less concerned about risks compared to those of non-medical staff (p < 0.05). Participants with higher income levels were more confident (p < 0.05), while those surveyed after the COVID-19 pandemic, who were mothers, who had an older child, or who were raising a second or above birth child, had less concern about risks (p < 0.05).

Discussion

We found that the VHS had acceptable reliability and construct validity and caregivers' hesitancy was driven more by concerns about risks than by the lack of confidence. Countering these concerns will be particularly important among non-medical staff, lower income, child's fathers, having a younger child, or raising first-birth child groups.

Analysis on vaccine hesitation and its associated factors among parents of preschool children in Songgang Street, Shenzhen

China has the largest number of vaccinated population around the world. However, there has been few research on the prevalence and associated factors of vaccine hesitation among parents of preschool children. Therefore, we conducted this study to evaluate the status of vaccine hesitation and its associated factors among children's parents. A cluster random sampling method was adopted to select six community health service centers in Shenzhen, and parents of preschool children who were immunized in the vaccination outpatient department of the selected community health centers were surveyed using a structured self-administered questionnaire. Vaccine hesitation was assessed by the Parent Attitudes about Childhood Vaccines (PACV) scale. A multiple linear regression analysis was used to assess the associated factors for vaccine hesitance among children's parents. A total of 1025 parents (response rate, 93.18%) filled out the questionnaires. The average score of vaccine hesitancy was 43.37 (SD = 10.34) points. 23.61% of parents wanted children to get all the recommended shots, 53.76% of them did not believe that many of the illnesses shots prevent were severe, and 75.41% of them could not guarantee the information they receive about shots. The results of multiple linear regression showed that the number of children in the family (β = -0.93, 95% CI: -1.31 to 0.54), health status of the child (β = 0.47, 95% CI: 0.07 to 0.87), education level of the parents (Father: β = -0.84, 95%CI: -1.37 to 0.31; Mother: = -1.59, 95%CI:-2.13 to -1.05), and annual family income (β = 1.64, 95%CI: 1.13-2.16) were significantly associated with vaccine hesitation. The average score of parents' vaccine hesitation in Shenzhen was 43.37. The results showed that the number of children in the family, health status of the children, education level of the parents and annual family income were important factors associated with the parents' vaccine hesitation.

Vaccine bidding, procurement and distribution management practices in mainland China: A nationwide study

OBJECTIVE

To conduct a nationwide evaluation of vaccine bidding, procurement and distribution management for understanding and improving the current situation well in mainland China.

METHODS

An institution survey was carried out to collect information on tendering, procurement, distribution and related issues to vaccines by structured questionnaires administered to 31 provinces in mainland China from April to July 2019.

RESULTS

In 13 (41.9%) of 31 provinces, centralized bidding of National Immunization Program (NIP) vaccines was accomplished, and others conducted independent tendering and purchasing in 2018. For non-NIP vaccines, all provinces implemented unified bidding at the provincial level and over half (18, 58.1%) of them chose provincial public resource trading platforms, but their modes varied over provinces. Then procurement was undertaken by the district-level centers for disease control and prevention (CDC) while they were unable to choose the best option of too many vaccines targeted by the province-level CDC for local populations. The distribution modes of NIP and non-National Immunization Program (non-NIP) vaccines were similar overall in a province but very different over provinces. Main mode was that CDCs at different levels delivered about two thirds (64.5%) of NIP vaccines distribution and more than one third (35.5%) of non-NIP vaccines. Another distribution mode was occupied as fully buying the service from third parties in 3 municipalities. Some provinces mixed both modes, too. The total distribution volume of vaccines was 430.7 million doses in 2018. The top five non-NIP vaccines delivered in 2018 were human rabies vaccine, varicella vaccine, EV71 hand foot mouth disease vaccine, hepatitis B vaccine and influenza vaccine.

CONCLUSION

The vaccine biding, procurement and distribution management varied over provinces in mainland China in 2018, especially for non-NIP vaccines. Specific policies and measures should be developed for different regions to improve the immunization management better.

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.

Acceptance of a COVID-19 Vaccine Before it is Available in China During the Pandemic

Objectives: China was believed to be the country with the world’s highest acceptance rate of the COVID-19 vaccine following several investigations. This study aims to explore the Chinese acceptance of a COVID-19 vaccine before it is made available, including its determinants.

Methods: A cross-national online survey was conducted covering all 31 provinces of mainland China. The survey consists of the demographic variables, acceptance of a self-paid COVID-19 vaccine as the dependent variable, and the 3Cs factors (i.e., confidence, convenience, and complacency) as the independent variables.

Results: Among the 1,532 participants, 57.9% accepted to get a self-paid COVID-19 vaccine. COVID-19 vaccine acceptors were more likely to be concerned about the effectiveness of the vaccines, believe that they were at risk of COVID-19 infection, have a high perceived susceptibility of COVID-19, and trust in the health care system.

Conclusion: Findings indicate that the critical task in the early stage of the COVID-19 vaccine development in China is to increase the tolerance to some intuitive concerns about the vaccines, put more emphasis on the communication of the saliency of the disease threats, and effectively translate people’s trust in the government into vaccine acceptance.

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 (β = −0.349, p < 0.001) and convenience (β = −0.232, p < 0.001), and positively with complacence (β = 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.

Access to Vaccination Information and Confidence/Hesitancy Towards Childhood Vaccination: A Cross-Sectional Survey in China

Access to vaccination information could influence public attitudes towards vaccination. This study investigated the number and types of vaccination-related information sources, and estimated their associations with vaccine confidence and hesitancy in China. In January 2019, we conducted a cross-sectional survey in China, and 2122 caregivers with children <6 years completed self-administered questionnaires. Logistic regressions were used to assess associations between caregivers’ primary information sources and vaccine confidence/hesitancy. A majority (72%) of caregivers had multiple sources of vaccination-related information. The proportions of caregivers reporting professional sources, media, and peers as primary information sources were 81%, 63%, and 26%. Internal migrants were less likely to get information from professional sources; more educated and wealthier caregivers reported more information sources and were more likely to get information from media and peers. Caregivers who reported professional information sources had significantly higher odds of being confident about the safety of vaccines and lower odds of being hesitant toward vaccination than those who did not. Caregivers who reported the media as a primary information source had significantly higher odds of being hesitant toward vaccination than those who did not. To address vaccine hesitancy, it is essential to promote universal access to professional vaccination-related information sources, and to use the media to disseminate evidence-based information and clarify misinformation. Health communication should target internal migrants, and more educated and wealthier caregivers.

Post-marketing safety surveillance for inactivated Enterovirus 71 vaccines in Jiangsu, China from 2017 to 2019

INTRODUCTION

Two types of enterovirus 71 (EV71) vaccines, manufactured using human diploid (H2) and Vero cells, have been administered in Jiangsu Province, China since 2017. In this study, we evaluated their safety profiles using records collected from the Chinese National Adverse Events Following Immunization (AEFIs) Information System (CNAEFIS) and Electronic Immunization Registries System (EIRS) between 2017 and 2019.

METHODS

Demographic characteristics of the patients, AEFI incidence rates(IRs), symptoms, and time intervals were summarized from the reported AEFI data in the CNAEFIS. Also, the administered doses of the two vaccines were exported from the EIRS to calculate the IRs of AEFIs and thus compare the AEFIs between the two types of EV71 vaccines.

RESULTS

In total, 209, 407, and 344 AEFIs cases following EV71 vaccine administration were reported during 2017, 2018, and 2019, respectively, yielding IRs of 59.2, 48.2, and 54.2 per 100,000 doses, respectively. Fever, irritability, allergic eruptions, fatigue, loss of appetite, redness and induration at the injection site were the most commonly reported AEFIs. No significant differences in rare reactions were found between the two types of EV71 vaccinations. The majority of AEFIs were developed within 30 min to 3 days after administration.

CONCLUSION

EV71 vaccines showed satisfactory safety profiles since their first use 3 years ago in the Jiangsu Province. The AEFI profiles were identical to those in pre-marketing studies; most AEFIs after vaccination were mild and common. More active surveillance studies should be performed to provide more comprehensive post-marketing safety data.