Comparative assessment of immunization coverage of migrant children between national immunization program vaccines and non-national immunization program vaccines in East China

The impact of the COVID-19 pandemic on childhood vaccination rates and the role of sociodemographic factors: A cohort study

OBJECTIVE

This study examines the impact of the COVID-19 pandemic on both routine and non-routine vaccinations in infants during their initial 18 months of life, concurrently exploring the complex influence of sociodemographic factors.

METHODS

A cohort study was conducted, involving 2007 children in two distinct periods: pre-pandemic (January-June 2018) and pandemic (March 2020-May 2021). Participants were classified into two cohorts: 962 children in the 2018 group and 1045 children in the 2020-21 group. Utilizing unconditional logistic regression, the association between vaccination (complete or non-routine) and socioeconomic factors was examined, with adjustments for potential confounding variables such as age, breastfeeding, gestational age, and twins.

RESULTS

The study's analysis reveals that in the post-pandemic period, mothers were three times more likely to opt for non-routine vaccines (95% CI 2.25-4.23). However, no significant alterations were observed in routine vaccination rates. Protective factors for complete vaccination included having an employed mother, higher education, and a medium-to-high income. Conversely, a higher income was associated with a reduced likelihood of complete vaccination (OR 0.34, 95% CI 0.20-0.59).

CONCLUSION

Contrary to initial expectations, this study concludes that the COVID-19 pandemic did not have a substantial impact on childhood complete vaccination rates. Nevertheless, a noticeable increase in the choice of non-routine vaccination was observed. Sociodemographic factors, such as maternal education, income, and employment status, emerged as key influencers, particularly in the context of deciding on non-routine vaccinations.

Determinants of parental demand of human papillomavirus vaccination for adolescent daughters in China: Contingent valuation survey

BACKGROUND

Several types of human papillomavirus (HPV) vaccines have been approved for use in adolescent girls in China. These vaccines are regulated as non-National Immunisation Program vaccines and are optional and generally fully self-paid by vaccinees.

OBJECTIVE

To assess parents' demand for HPV vaccination by eliciting their willingness-to-pay for their adolescent daughters to be vaccinated against HPV and to examine the determinants of demand for HPV vaccination in China.

METHODS

A contingent valuation survey was conducted across three cities in Shandong Province in eastern China. We selected 11 junior middle schools with different socioeconomic features and randomly selected 6 classes in each school, and questionnaires were distributed to all girls aged 12-16 in the 66 classes for their parents to complete. A payment card approach was used to elicit parental willingness-to-pay for HPV vaccination for their daughters. We also collected a wide array of socioeconomic and psychological variables and interval regressions were applied to examine the determinants of parental willingness-to-pay.

RESULTS

A total of 1074 eligible parents who completed valid questions were included in analyses. Over 85% of parents believed HPV vaccines were, in general, necessary and beneficiary. However, only around 10% believed that their daughters would be infected by HPV. About 8% of parents would not accept HPV vaccine even if the vaccine were free mainly due to concerns about the potential side effects and vaccine safety and quality issues, and 27.37% would only accept the vaccine if it were free. The median willingness-to-pay was 300 CNY (42 USD). Several factors were positively correlated with higher willingness-to-pay: income, urban residence (relative to rural residence), mothers (relative to fathers), parents' beliefs about vaccine benefits, whether they should make decisions for their daughters, and whether their daughters would be susceptible to HPV. Though education-level was not significantly correlated with willingness-to-pay in the main regressions, a subgroup analysis revealed interesting dynamics in the relation between education and willingness-to-pay across different income-levels.

CONCLUSIONS

There is a large gap between parents' willingness-to-pay and the market price of HPV vaccine for girls in China. Parents generally believed the HPV vaccines were beneficial and necessary but when asked for their daughters, most parents did not believe their daughters would be infected by HPV despite the high prevalence in China. Future focus should be on ensuring the provision of accurate health information about HPV prevalence, vaccine quality, and safety to promote vaccine uptake, and promotional efforts tailored to different income groups might yield better effects. Government involvement in negotiating more widely acceptable and affordable prices or subsidising may be necessary for protecting high-risk population groups.

Current vaccination status and safety of children with peripheral neuroblastoma in the real-world

Background

peripheral neuroblastic tumors (pNT) have high incidence and mortality, and infants are prone to various infectious diseases. The purpose of this study is to understand the immunization status of children with pNT in the real-world and the incidence of adverse reactions after vaccination, and to evaluate the feasibility of vaccination and the influencing factors of vaccination.

Methods

Children with pNT treated in the Children's Hospital Affiliated to Zhejiang University from January 1, 2011 to December 1, 2021 were included. By referring to medical records, the vaccination history of the national immunization program (NIP) vaccines and the occurrence of adverse events following immunization(AEFI), current status and safety of immunization in children with pNT in the real-world were analyzed.

Results

Among 784 children with pNT, 394 were able to obtain the history of vaccination. The overall vaccination rate of NIP vaccines was 71.49% before chemotherapy and 37.67% after chemotherapy, and the recovery time of vaccination after treatment was 16.00 (6.00,24.00) months. Age, time of tumor diagnosis and disease classification were significantly correlated with vaccination. AEFI reported an incidence of 0.23‰.

Conclusion

The vaccination rate of children with pNT is generally low, especially the vaccination rate after chemotherapy. The vaccination safety is good, children should be encouraged to immunize.

Immunization coverage, knowledge, satisfaction, and associated factors of non-National Immunization Program vaccines among migrant and left-behind families in China: evidence from Zhejiang and Henan provinces

BACKGROUND

Migrant and left-behind families are vulnerable in health services utilization, but little is known about their disparities in immunization of non-National Immunization Program (NIP) vaccines. This study aims to evaluate the immunization coverage, knowledge, satisfaction, and associated factors of non-NIP vaccines among local and migrant families in the urban areas and non-left-behind and left-behind families in the rural areas of China.

METHODS

A cross-sectional survey was conducted in urban areas of Zhejiang and rural areas of Henan in China. A total of 1648 caregivers of children aged 1-6 years were interviewed face-to-face by a pre-designed online questionnaire, and their families were grouped into four types: local urban, migrant, non-left-behind, and left-behind. Non-NIP vaccines included Hemophilus influenza b (Hib) vaccine, varicella vaccine, rotavirus vaccine, enterovirus 71 vaccine (EV71) and 13-valent pneumonia vaccine (PCV13). Log-binomial regression models were used to calculate prevalence ratios (PRs) and 95% confidence intervals (CIs) for the difference on immunization coverage of children, and knowledge and satisfaction of caregivers among families. The network models were conducted to explore the interplay of immunization coverage, knowledge, and satisfaction. Logistic regression models with odds ratios (ORs) and 95% CIs were used to estimate the associated factors of non-NIP vaccination.

RESULTS

The immunization coverage of all non-NIP vaccines and knowledge of all items of local urban families was the highest, followed by migrant, non-left-behind and left-behind families. Compared with local urban children, the PRs (95% CIs) for getting all vaccinated were 0.65 (0.52-0.81), 0.29 (0.22-0.37) and 0.14 (0.09-0.21) among migrant children, non-left-behind children and left-behind children, respectively. The coverage-knowledge-satisfaction network model showed the core node was the satisfaction of vaccination schedule. Non-NIP vaccination was associated with characteristics of both children and caregivers, including age of children (> 2 years-OR: 1.69, 95% CI: 1.07-2.68 for local urban children; 2.67, 1.39-5.13 for migrant children; 3.09, 1.23-7.76 for non-left-behind children); and below caregivers' characteristics: family role (parents: 0.37, 0.14-0.99 for non-left-behind children), age (≤ 35 years: 7.27, 1.39-37.94 for non-left-behind children), sex (female: 0.49, 0.30-0.81 for local urban children; 0.31, 0.15-0.62 for non-left-behind children), physical health (more than average: 1.58, 1.07-2.35 for local urban children) and non-NIP vaccines knowledge (good: 0.45, 0.30-0.68 for local urban children; 7.54, 2.64-21.50 for left-behind children).

CONCLUSIONS

There were immunization disparities in non-NIP vaccines among migrant and left-behind families compared with their local counterparts. Non-NIP vaccination promotion strategies, including education on caregivers, and optimization of the immunization information system, should be delivered particularly among left-behind and migrant families.

Factors associated with recommendation behaviors of four non-National Immunization Program vaccines: a cross-sectional survey among public health workers in China

BACKGROUND

Immunization is a crucial preventive measure to safeguard children under five years old against a range of diseases. In China, the coverage rate of non-National Immunization Program (non-NIP) vaccines can be improved by leveraging the recommendation from public health workers. Hence, understanding the influencing factors of recommendation behaviors assume paramount importance. This study aims to investigate influencing factors of public health workers' recommendation behaviors towards non-NIP vaccines, with a particular emphasis on financial incentives.

METHODS

A cross-sectional survey was conducted using a multi-stage sampling method in 2019 from August to October. 627 public health workers were recruited from 148 community healthcare centers in ten provincial-level administrative divisions in China. An anonymous questionnaire was used to collect demographic information, attitudes towards vaccination, and recommendation behaviors towards non-NIP vaccines, including Haemophilus influenzae type b (Hib) vaccine, pneumococcal conjugate vaccine, varicella vaccine, and rotavirus vaccine. Descriptive analysis and multivariate logistic regression analysis were adopted in this study.

RESULTS

Of the 610 public health workers with complete survey data, 53.8%, 57.4%, 84.1%, and 54.1% often recommended Hib vaccine, pneumococcal pneumonia vaccine (PCV), varicella vaccine, and rotavirus vaccine, respectively. Logistic regression revealed that gender (Hib vaccine: OR = 0.4, 95% CI: 0.2-0.8; PCV: OR = 0.4, 95% CI: 0.2-0.8; rotavirus vaccine: OR = 0.3, 95% CI: 0.2-0.6), financial incentives for non-NIP vaccination (Hib vaccine: OR = 1.9, 95% CI: 1.1-3.6; PCV: OR = 2.1, 95% CI: 1.1-3.9; rotavirus vaccine: OR = 2.0, 95% CI: 1.1-3.8) and perception of vaccine safety (Hib vaccine: OR = 2.7, 95% CI: 1.1-7.0; PCV: OR = 3.2, 95% CI: 1.2-8.0; rotavirus vaccine: OR = 3.0, 95% CI: 1.2-7.7) were associated with public health workers' recommendation towards Hib vaccine, PCV and rotavirus vaccine.

CONCLUSIONS

The findings highlighted public health workers' recommendation behaviors of non-NIP vaccines in China and revealed strong association between vaccine recommendation and financial incentives. This highlights the importance of financial incentives in public health workers' recommendation toward non-NIP vaccines in China. Proper incentives are recommended for public health workers to encourage effective health promotion in immunization practices.

Vaccine hesitancy and receipt of mandatory and optional pediatric vaccines in Shanghai, China

Given increased global concern about vaccine hesitancy, this study estimates coverage of mandatory vs non-mandatory vaccines in children, and assesses whether vaccine hesitancy among young parents relates to their child's eventual vaccination status in Shanghai, China. In a cohort study within Shanghai, China, we ascertained vaccine hesitancy among parents of young infants, and later abstracted their child's electronic immunization records. We measure full coverage of vaccines on the mandatory, and publicly funded Expanded Program on Immunization (EPI). Non-EPI vaccines included pneumococcal conjugate vaccine, Haemophilus influenzae type b vaccine, and rotavirus vaccine. Vaccine hesitancy was linked to vaccine uptake through mixed effects logistic regression models. Among 972 children, full coverage of all EPI vaccines by 15 months was 95%, compared to dose 1 coverage of pneumococcal conjugate vaccine at 13%, Haemophilus influenzae type b vaccine at 68%, and rotavirus vaccine at 52%. Vaccine hesitancy was not significantly linked with full coverage of all EPI vaccines (OR: 1.55, 95% CI: .89, 2.72), but coverage in the vaccine hesitant was lower for pneumococcal conjugate vaccine dose 1 (OR: .70, 95% CI: .53, .91), and rotavirus vaccine dose 1 (OR: .69, 95% CI: .56, .86). Disparities by education level were not significant for EPI vaccines, but were for dose 1 of pneumococcal conjugate vaccine rotavirus vaccine. Overall, vaccine hesitancy was related to lower uptake of non-EPI, but not EPI vaccines. Shanghai has a robust system for insurance equitable access to EPI vaccines, but if vaccine hesitancy grows, it could reduce coverage of non-EPI vaccines.

Parental preference for Haemophilus influenzae type b vaccination in Zhejiang Province, China: A discrete choice experiment

Background

China is the only country in the world that has not included the Haemophilus influenzae type b (Hib) vaccine in its National Immunization Program, making it more difficult to eliminate Hib-related diseases through Hib vaccination. It is necessary to study parental preferences for Hib vaccination to optimize vaccine promotion strategies in China.

Objective

This study aimed to investigate Chinese parental preference for five attributes of Hib vaccination, i.e., the place of origin, effectiveness, adverse event, doctors' recommendation, and the price of full vaccination when making a decision to vaccinate their children under 2 years old.

Methods

A cross-sectional survey was conducted in two cities in Zhejiang Province from November to December in 2020 using a discrete choice experiment (DCE). A mixed logit model was used to estimate participating parents' preference for Hib vaccination attributes included in the DCE. Subgroup analysis and probability analysis were also conducted to capture the heterogeneity and trade-off of parental preference for Hib vaccination.

Results

Data from 6,168 observations were included in the analyses. Parents of children are, on average, more likely to voice a positive preference for Hib vaccination. Such attributes of Hib vaccination as effectiveness and doctor's recommendation have a significant positive influence on parents' preference for Hib vaccination, while imported vaccines, adverse events, and the price of full vaccination have a significant negative influence on parents' preference. Parents with different demographic characteristics also existed heterogeneities in preference for Hib vaccination. Parents will make a trade-off on price if the Hib vaccine has a good performance on effectiveness and safety.

Conclusion

The study found that, regardless of the place of origin of the Hib vaccine, parents with children under 2 years old prefer to compromise on price if the vaccine has a better effectiveness and safety profile. A proactive recommendation from doctors would strengthen their willingness for Hib vaccination. These findings help aid the development of communication strategies with parents for Hib vaccination in China.

Measuring parents' acceptance of non-national immunization program vaccines for children and its influencing factors during the COVID-19 pandemic in Shanghai, China

This study aimed to understand the willingness of and affecting factors of non-national immunization program (non-NIP) vaccines among children's parents during the COVID-19 era in Shanghai, China. A cross-sectional survey was conducted with parents who attended vaccination clinics in four out of 16 districts in Shanghai, China. Data was obtained using a self-administered structured questionnaire. A multivariate logistic regression model was used to analyze factors associated with vaccination acceptability. In total, 1691 valid questionnaires were obtained. Of the participants, 69.5% (1,176/1,691) reported being interested in non-NIP vaccines for their children. Further, respondents were more likely to be willing to get non-NIP vaccines for their children if they had an income of 10,000-20,000CNY or more, an educational level of college or above, and if getting the vaccination was moderately convenient or convenient. Respondents were less likely to be willing to get the vaccines if they were in the 30-39 age group and had moderate or low satisfaction with the vaccine. Many parents are willing to get non-NIP vaccines for their children. However, some demographic factors, perceived convenience and satisfaction of vaccination, perceived necessity, safety and price barrier of non- NIP influenced the acceptability of non-NIP vaccines in Shanghai. Our findings can help guide future efforts to increase non-NIP vaccines acceptability.

Effect of pneumococcal conjugate vaccine availability on Streptococcus pneumoniae infections and genetic recombination in Zhejiang, China from 2009 to 2019

Pneumococcal pneumonia is one of the main reasons for child death worldwide. Pneumococcal conjugate vaccines (PCVs) are considered the most effective strategy for pneumococcal disease (PD) prevention, but how a pause in PCV vaccination affects the prevalence of PD or the genetic evolution of Streptococcus pneumoniae genetic evolution is unknown. Based on the unique PCV introduction timeline (vaccine unavailable during April 2015-April 2017) in China, we aimed to evaluate the effect of interrupted PCV availability on PD and pneumococcal genome variation. Pneumococcal isolates (n = 386) were collected retrospectively from eight sites in Zhejiang, China from 2009 to 2019 in which 184 pathogenic (isolates from sterile and infection sites) strains were identified. An interrupted time series analysis was conducted to estimate changes in PD and the recombination frequency of whole genome-sequenced strains was estimated via SNP calling. We found that both PD and pneumococcal genome variation were affected by interrupted PCV availability. The proportion (∼70%) of vaccine-type pneumococcal LRTI (VT-LRTI) in all LRTI cases decreased to ∼30% in the later PCV7 period and rebounded to ∼70% in children once PCV7 became unavailable in April 2015 (p = 0.0007). The major clone CC271 strains showed slowed (p = 0.0293) recombination frequency (decreased from 2.82 ± 1.16–0.72 ± 0.21) upon PCV removal. Our study illustrated for the first time that VT-LRTI fluctuated upon interrupted vaccine availability in China and causing a decreased of recombination frequency of vaccine types. Promoting a nationwide continuous vaccination programme and strengthening S. pneumoniae molecular epidemiology surveillance are essential for PD prevention.

Vaccine hesitancy among parents and its influencing factors: a cross-sectional study in Guangzhou, China

Vaccine hesitancy is a major obstacle to the achievement of universal child vaccination, which has been studied extensively in Western countries but much less so in Asian countries, especially China. This cross-sectional survey is aimed to assess the prevalence of vaccine hesitancy and to explore the reasons for vaccine hesitancy among parents in Guangzhou. In January 2020, a questionnaire adapted to the Chinese setting from a widely-used hesitancy scale was administered to a sample of parents who brought their children aged <13 years to Community Health Service Centers for vaccination in Guangzhou. The incidence of vaccine hesitancy among those parents was 6.6% (50/755). Regression analysis showed that differences in socio-economic characteristics were not associated with the occurrence of vaccine hesitancy among parents in Guangzhou. However, strong distrust of domestic vaccine quality (OR = 10.9, 95% CI = 1.5-81.4), being required to have their children vaccinated for nursery and school entry (OR = 3.6, 95% CI = 1.7-7.7), and not being aware of which vaccines are officially required and which are optional (OR = 2.1, 95% CI = 1.1-4.3) were the risk factors significantly associated with vaccine hesitancy. In order to increase parents' trust in domestic vaccine quality and reduce the prevalence of vaccine hesitancy, it is essential to strengthen quality control in domestic vaccine manufacturing and to proactively disseminate clear and accurate information about vaccines to parents. Furthermore, advocating the value of vaccination among all citizens of Guangzhou is crucial.

Vaccination experiences of premature children in a retrospective hospital-based cohort in a Chinese metropolitan area

BACKGROUND

In China, premature children in good health may be advised to receive routine immunization programs. However, delayed vaccination is common. This study aimed to characterize vaccination experiences of premature children and determine the impact of vaccination consultation clinic (VCC) assessment.

METHODS

We performed a retrospective cohort study, including premature children visiting VCC at Children's Hospital of Fudan University in 2017-2019. Data of these children, including demographics, recommendations of vaccination after VCC assessment, vaccination records, adverse events following immunization (AEFI), and incidence of vaccine-preventable diseases in 2017-2019, were collected retrospectively.

RESULTS

A total of 1124 premature children were included, with vaccination uptake of 46.3% for expanded program of immunization (EPI) vaccines and 15.1% for non-EPI vaccines before VCC assessment. Furthermore, 77.5% of premature children who had not received any EPI vaccine were vaccinated after the assessment; however, most were delayed, regardless of vaccine types and recommendations. In contrast, 67.3% was vaccinated with non-EPI vaccines after the assessment. Majority (n = 35) of recorded AEFI was mild to moderate, in addition to one allergic rash. One each case of pertussis and varicella were recorded in those who had not received the corresponding vaccines.

CONCLUSION

Vaccination may be safe and epidemiological effective in premature children. However, it remains mostly delayed in premature children with recommendations of normal vaccination. It warrants improving implementation of VCC recommendations. In addition, there is a need of health promotion on more non-EPI vaccines for premature children.

Genotypic and phenotypic characteristics of Streptococcus pneumoniae from community-acquired pneumonia patients and healthy asymptomatic participants in Sichuan province, China

Background

Streptococcus pneumoniae (S. pneumoniae) is the common cause of community-acquired pneumonia (CAP) and is also found in the upper respiratory tract of healthy people. Hence, the study aimed to compare the serotypes, virulence/pili genes, and antibiotic susceptibility of S. pneumoniae from healthy asymptomatic participants and CAP patients.

Methods

Streptococcus pneumoniae were retrospectively collected from health asymptomatic participants and CAP patients in Sichuan, China. The serotypes were tested by multiplex polymerase chain reaction (PCR) or Quellung reaction. Antibiotic susceptibility testing was performed using the broth microdilution method. The molecular epidemiology of S. pneumoniae was analyzed by multilocus sequence typing (MLST). Additionally, the presence of virulence/pili genes were detected using PCR.

Results

A total of 83 pneumococcal isolates were collected in the current study. Of these, 52 and 31 isolates were from healthy asymptomatic participants and CAP patients, respectively. Most of S. pneumoniae were resistant to erythromycin (ERY), clindamycin (CLI), tetracycline (TET) and trimethoprim-sulfamethoxazole (SXT). 90.4% isolates were classified as multidrug resistant (MDR). The predominant serotypes were 3, 19F and 19A in the CAP carriers, whereas 3, 6 and 19F were the main serotypes among the asymptomatic carriers. The overall coverage rates of pneumococcal conjugate vaccine (PCV) 10 and PCV13 serotypes were 34.9% and 66.3%, respectively. The predominant sequence types (STs) were ST271, ST320, and ST3397. There were significant differences in some resistance and virulence characteristics between CAP patients and asymptomatic carriers. Additionally, clonal complex (CC) 271 strains had higher percentage in resistance to cefuroxime (CXM) and cefotaxime (CEF), meropenem (MER) and cefepime (CFP), which mainly carried the rlrA and sipA genes.

Conclusions

High coverage rate of PCV13 and high prevalence of MDR indicated the necessity to expand immunization with PCV13 and rationally use the antibiotics in Sichuan, China. Importantly, long-term surveillance should be conducted to assess effectiveness brought by vaccines. Our findings may supply new guidance for developing new pneumococcal vaccines.

Evaluating the vaccination coverage: validity of household-hold vaccination booklet and caregiver's recall

BACKGROUND

We compared results from household data sources to medical record sources by using data from a vaccination coverage survey.

METHODS

Vaccination coverage (VC) was calculated based on parental recall, household vaccination booklet, and Zhejiang provincial immunization information system (ZJIIS). We evaluated the accuracy of VC based on household sources (vaccination booklet and recall) assuming the medical record was accurate. Concordance, sensitivity, specificity, positive predictive value, and negative predictive value were estimated as well as the Kappa statistic was also used to evaluate the agreement between data sources.

RESULTS

Among the 1,800 children identified in the household survey, all were registered in ZJIIS. VC estimated using the vaccination booklet alone was substantially lower than that based on medical records (net bias 3.4-16.7% in different age groups). VC based on parental recall ranged from 2.5% below (among children aged 1 year) to 16.7% points above (among children aged 6 years) than those based on medical records. Concordance was lowest for card estimates (32.5-45.5%). Sensitivity was <60% for all household sources, except for recall source. Specificity was lowest for recall estimates (14.5-42.6%). Positive predictive value was >75%, while negative predictive value was <50%, for all household sources. Kappa statistics generally indicated poor agreement between household and medical record sources.

CONCLUSIONS

Household-retained vaccination booklets and parental recall were insufficient sources for evaluating the VC. Our findings emphasized the importance of taking interventions to make the vaccination booklet more consistent with the records from medical resource.

The trends of socioeconomic inequities in full vaccination coverage among children aged 12-23 months from 2000 to 2017: evidence for mitigating disparities in vaccination service in Zhejiang province

OBJECTIVE

This study aimed to evaluate the trends and changes in inequities in the completeness of the primary vaccination (CPV) scheduled before the first year of age among children aged 12-23 months, from 2000 to 2017. Methods: Data were extracted from five rounds of the provincial vaccination coverage survey (PVCS) in 2000, 2004, 2008, 2014 and 2017, respectively. The household income per month was used as an index of socioeconomic status for the inequity analysis. The concentration index (CI) was used to quantify the degree of inequity, and the decomposition approach was applied to quantify the contributions from independent factors to inequity in the CPV. Results: The CPV was significantly improved from 2000 to 2017, with 67.0% for the 2000 PVCS and 86.0% for the 2017 PCVS. The CI value decreased from 0.29839 for the 2000 round to 0.03601 for the 2017 round. The decomposition analysis indicated that independent variables such as birth order, ethnic group, mother's education, maternal employment status, residence, immigration status and the percentage of the total health spending allocated to public health could explain the inequity in the CPV in varying degrees. Conclusions: A sharp reduction in socioeconomic inequity in the CPV was observed from 2000 to 2017. Policy recommendations to reduce the inequality in the CPV should focus on children with the risk factors found in this study, for better outcome in full vaccination and long-lasting herd immunity.

Vaccination recommendations, immunization status and safety of vaccination for premature infants in Zhejiang, China

OBJECTIVES

More and more premature infants were born worldwide that are suffering from various complications, vaccination for whom is often delayed in China. We aim to describe current vaccination recommendations in practice, immunization status, and vaccination safety for premature infants in Zhejiang.

METHODS

The demographic information, medical records of treatments, and adverse events following immunization (AEFI) history were collected from infants' parents by questionnaire in the Vaccination Consultation Clinic(VCC). Vaccination data were retrieved from Zhejiang Provincial Immunization Information System. The information of AEFI was collected from the Chinese National Adverse Event Following Immunization Information System.

RESULTS

A total of 1515 premature infants visiting the VCC were included in the study. The majority (65.94%) of them were under 7 months. 47.59% of premature infants were advised to receive normal vaccinations, while 45.94% were advised to defer a specific vaccination and 6.47% were advised to defer all vaccinations. A total of 807 infants received 7187 vaccine doses were administered and only seven cases experienced mild and self-limiting adverse reactions (9.74/10,000). No uncommon or serious side effects were reported.

CONCLUSION

Most premature infants visiting the VCC did not receive vaccines on time. The majority of them can be safely vaccinated according to the national-recommended schedule.

Vaccination coverage and its determinants of live attenuated hepatitis A vaccine among children aged 24-59 months in 20 rural counties of 10 provinces of China in 2016

OBJECTIVE

To understand one single dose coverage of live attenuated hepatitis A vaccine and its determinants among children aged 24-59 months in 20 rural counties of 10 provinces of China in 2016.

METHODS

In 20 counties, using three-stage probability proportion to size sampling, 1979 children aged 24-59 months with a vaccination card were selected from 20 rural counties in 2016. Socio-demographic and socio-economic characteristics of children and their caregivers were acquired from face-to-face questionnaire survey and copies of the vaccination cards. We used multivariate logistic regression models to identify the determinants of one single dose coverage of live attenuated hepatitis A vaccine.

RESULTS

In 2016, the overall one single dose coverage of live attenuated hepatitis A vaccine among children aged 24-59 months in rural areas of China was 77.1%. The adjusted analysis showed that being in second birth order (adjusted OR: 1.40; 95%CI: 1.03-1.90), being in third birth order or more (adjusted OR: 2.10; 95%CI: 1.26-3.51), being born at home (adjusted OR: 2.01; 95%CI: 1.04-3.88) and having the lowest per capita income of household (adjusted OR: 2.36; 95%CI: 1.11-4.99) were significantly related to being unvaccinated one single dose coverage of live attenuated hepatitis A vaccine against hepatitis A virus.

CONCLUSION

one single dose coverage of live attenuated hepatitis A vaccine was still at a low level in 20 rural counties of 10 provinces in China. To improve the coverage of live attenuated hepatitis A vaccine, the government should pay more attention to the disadvantaged groups, especially the children who were in second birth order or higher, or delivered at home, or who have the lowest per capita income of household.

Are providers' recommendation and knowledge associated with uptake of optional vaccinations among children? A multilevel analysis in three provinces of China

BACKGROUND

Immunization services providers play a crucial role in the successful implementation of immunization, particularly for new vaccines. Several childhood vaccinations that are important for public health are not included in the National Immunization Programme in China, although they are available as optional and self-paid vaccines. Their coverage remains low.

OBJECTIVE

To examine the association between providers' knowledge and recommendations of optional vaccines, as well as other supply- and demand-side factors, and their uptake among children.

METHODS

A cross-sectional study, that included an in-person questionnaire survey for parents of children under-3 years and a self-administrative questionnaire survey for their vaccination services providers, was conducted in 36 townships or sub-districts in three provinces of China in 2013. Using a sample of 1791 household from 30 townships or sub-districts, we applied multilevel logistic analyses to examine the factors associated with the uptake of optional vaccines based on a hierarchal framework that combined demand-side and supply-side factors.

RESULTS

Coverage of optional childhood vaccinations varied across small areas. Supply- and demand-side factors were both associated with the uptake of these vaccines. Immunization services providers' recommendations and their knowledge about optional vaccination were positively and significantly associated with uptake. Children were more likely to receive the vaccines if they lived in communities with higher immunization worker density or larger immunization clinics. Several demand-side psychological factors about childhood vaccination were also associated with optional vaccinations.

CONCLUSIONS

Promoting immunization services providers to conduct evidence-based recommendations about some important childhood optional vaccinations and enhancing their knowledge regarding optional vaccinations and communication skills are useful strategies to increase the coverage of these vaccinations.

Coverage of Haemophilus influenzae Type b Conjugate Vaccine for Children in Mainland China: Systematic Review and Meta-analysis

BACKGROUND

Use of Haemophilus influenzae type b conjugate vaccine is effective in reducing the disease burden, but its coverage in China is unclear. The aim of this meta-analysis is to assess the coverage of Hib conjugate vaccines in children in Mainland China.

METHODS

We systematically searched Pubmed, Web of Science, Medline, CNKI and Wanfang to identify studies assessing the coverage of Hib vaccine in Chinese children. Random-effects models were used to obtain pooled estimates for Hib vaccine coverage and analyzed heterogeneity with meta-regression and subgroup analyses.

RESULTS

Thirty-three studies that included 7,227,480 subjects in 12 provinces met our inclusion criteria. The pooled overall coverage of Hib conjugate vaccine was 54.9% [95% confidence interval (CI): 52.9-57.0]. The pooled coverage for the nonlocal population (54.3%; 95% CI: 52.4-56.3) was lower than that for the local residents (62.0%; 95% CI: 58.4-65.6). The region-pooled coverage was higher in the east of China (59.7%; 95% CI: 57.3-62.1) than in the central and west parts of the country (48.5%; 95% CI: 40.6-56.4). Overall, 26.7% (95% CI: 20.1-33.2) had 1 dose only, 14.8% (95% CI: 10.0-19.6%) had 2 doses, 13.5% (95% CI: 9.1-17.8) had 3 doses and 14.3% (95% CI: 9.7-18.9) had 4 doses.

CONCLUSIONS

We found a low coverage of Hib conjugate vaccine, particularly for the nonlocal children and those living in the central and west parts of China. Including Hib vaccine into the national immunization program is recommended to reduce disparities in vaccination coverage.

Hepatitis B Vaccination among 1999⁻2017 Birth Cohorts in Zhejiang Province: The Determinants Associated with Infant Coverage

This study aimed to investigate the coverage of hepatitis B vaccine (Hep B) and its completeness and timeliness for birth cohorts from 1999 to 2017 in Zhejiang province, East China. Demographic characteristics and vaccination records of Hep B of children born from 1 January 1999 to 31 June 2017 were extracted from the Zhejiang provincial immunization information system. The timeliness of the first dose of Hep B (Hep B1) was defined as the proportion of children who received the Hep B1 within 24 h after birth among the target population. The completeness of Hep B was defined as the proportion of children who completed the three-dose series of Hep B before 7 years of age. The demographic characteristics of the target population were described. The coverage of each dose of Hep B, the timeliness of Hep B1, and the completeness of Hep B for each birth cohort were described. A logistic regression model was applied to detect the determinants of the timeliness of Hep B1 and the completeness of Hep B vaccination. The coverage of Hep B1 increased from 90.3% to 98.3%, the coverage of Hep B2 increased from 88.8% to 96.1%, and the coverage of Hep B3 increased from 86.4% to 94.2%. The timeliness of Hep B1 increased from 80.3% to 91.3%. The completeness of Hep B increased from 81.3% to 91.5%. The determinants of timeliness of Hep B1 included children’s delivery place, immigration status, maternal education level, and economic development level of resident area. The determinants of completeness of Hep B included children’s delivery place, immigration status, maternal education level, economic development level of resident area, maternal occupation, and frequency of vaccination service. Zhejiang province had achieved significant improvements in the timely administration of Hep B1 and the completeness of Hep B. To accelerate progress toward additional reductions in the transmission of hepatitis B virus, further efforts need to be focused on improving the timeliness of Hep B1 vaccination and reducing the drop-outs among disadvantaged children with the risk factors identified in this study.

Factors associated with and screening models of national immunization programme vaccine series completion among preschool children in Fujian Province, south-eastern China

BACKGROUND

An effective method for the rapid identification of vulnerable preschool children at risk of not completing the national immunization programme (NIP) vaccine series in China is still lacking.

METHODS

A cross-sectional study involving 772 preschool children born between September 1 2009 and August 31, 2011 was conducted in 2015 in Fujian Province, south-eastern China. The data were collected by face-to-face interviews with the parents or guardians of the children using a standard questionnaire.

RESULTS

Children who received the first dose of a hepatitis B vaccine (HepB) less than 24h after birth and those who received one or more doses of surrogate for-fee vaccines (SFVs) were more likely to complete the NIP vaccine series with adjusted odds ratios (ORs) of 3.12 (95% confidence interval [CI]: 1.19-8.23) and 4.74 (1.41-15.90), respectively. The cut-off value of the prediction score for the completion of the NIP vaccine series was 92.5%, and the sensitivity, specificity, and positive and negative predictive values were 87.5%, 47.1%, 11.4% and 98.0%, respectively.

CONCLUSIONS

The receipt of a timely first dose of HepB and one or more doses of SFVs were associated with and good predictors of NIP vaccine series completion by preschool children in Fujian, China.

An Overview of Coverage of BCG Vaccination and Its Determinants Based on Data from the Coverage Survey in Zhejiang Province

To assess the Bacille Calmette-Guérin (BCG) vaccination coverage in Zhejiang province and to investigate predictors of the BCG vaccination, we used data from the 2017 Zhejiang provincial coverage survey. Demographic and immunization data on the selected children, their mothers, and their families were also collected by using a pre-tested questionnaire. BCG scars were verified among children who were available at the moment of survey. Coverage of BCG and other expanded program on immunization (EPI) vaccines scheduled before the first year of life was calculated. BCG coverage through the scar assessment and timeliness of BCG were also presented. Multivariate analyses of the predictors associated with the BCG vaccination and its timeliness were conducted separately. In total, 1393 children agreed to participate in the survey and presented the immunization cards. Of them, the coverage of BCG was 92.0% and 88.3% received the BCG within the first 28 days after birth. Besides this, 1282 out of the 1393 children were screened for the BCG scars and 97.1% of them had developed the scars. The multivariable logistic regression analyses indicated that hospital delivery, higher maternal education, a mother with no job, and a resident child were positively associated with the higher BCG vaccination coverage and its timely administrations. BCG coverage was optimal and it was administered in a timely manner. The majority of children vaccinated with BCG developed scars. Tailored interventions should be more greatly focused on and targeted to children with the risk factors identified in this study.

Evaluation of potentially achievable vaccination coverage of the second dose of measles containing vaccine with simultaneous administration and risk factors for missed opportunities among children in Zhejiang province, east China

OBJECTIVES

This study aimed to evaluate the potential achievable coverage of the second dose of measles containing vaccine (MCV2) when the protocol of simultaneous administration of childhood vaccines was fully implemented. Risk factors for missed opportunity (MO) for simultaneous administration of MCV2 were also investigated.

METHODS

Children born from 1 January 2005 to 31 December 2014 and registered in Zhejiang provincial immunization information system were enrolled in this study. The MO of simultaneous administration of MCV2, the actual age-appropriate coverage (AAC) of MCV2 and the potentially achievable coverage (PAC) of MCV2 were evaluated and compared across different birth cohorts, by different socio-demographic variables. For the 2014 birth cohort, logistic regression model was used to detect the risk factors of MOs, from both socio-demographic and vaccination service providing aspects.

RESULTS

Compared to the AAC, the PAC of MCV2 increased significantly from 2005 birth cohort to 2014 birth cohort (p<0.001), with a median of 12.7 percentage points. Higher birth order of children, resident children, higher maternal education background, higher socio-economic development level of resident areas, less frequent vaccination service, and shorter vaccination service time were significant risk factors of MO for simultaneous administration of MCV2, with all p-value < 0.05.

CONCLUSION

The findings in this study suggest that fully utilization of all opportunities for simultaneous administration of all age-eligible vaccine doses at the same vaccination visit is critical for achieving the coverage target of 95% for MCV2. Future interventions focusing on the group with risk factors observed could substantially eliminate MOs for simultaneous administration of MCV2, further to improve the coverage of fully immunization of MCV, and finally achieve the goal of eliminating measles.

Evaluation of two health education interventions to improve the varicella vaccination: a randomized controlled trial from a province in the east China

Background

We evaluated the effect of two Elaboration Likelihood Model (ELM)-based health educational interventions on varicella vaccine (VarV) vaccination among pregnant women in a province in the east China.

Methods

A prospective randomized controlled trial was conducted among 200 pregnant women with ≥12 gestation weeks to test two interventions, including a messaging video and a messaging booklet. The participants were randomly assigned into the control group, the video group or the booklet group. The VarV coverage at 12 and 24 months old was compared among the children of the three groups and relative risks (RRs) were calculated, by using the coverage of the control group as reference. The timeliness of VarV was also assessed. Furthermore, differences in the effects on the knowledge and attitude of VarV vaccination between the two interventions was evaluated.

Results

The VarV coverage of their children by 24 months of age was 86.4%, 76.1% and 56.7% for the video group, the booklet group and the control group, respectively. The relative risks (RRs) for the coverage of VarV at 24 months of age were 4.8 (95% CI: 2.06–11.3) for the video group and 2.4 (95% CI: 1.2–5.1) for the booklet group. The means of delays were 57.3 days in the video group, 76.9 days in the booklet group, and 100.6 days in the control group. The proportion of women who intended to vaccinate their children with VarV was higher in the video group than the booklet group (93.9% vs. 82.1%, p < 0.05).

Conclusions

Our findings indicated that perinatal health education through booklet or video could improve the coverage and schedule adherence for children’s VarV vaccination.

Knowledge, Attitude and Practice of Pregnant Women towards Varicella and Their Children's Varicella Vaccination: Evidence from Three Distrcits in Zhejiang Province, China

Background: The objectives of this study were to examine the knowledge, attitudes and practice (KAP) towards varicella and varicella vaccine (VarV) vaccination among pregnant women in three distrcits in Zhejiang Province, China. Methods: From 1 January to 31 March 2014, pregnant women with ≥12 gestational weeks were recruited and received a self-administrated questionnaire. The first dose of VarV (VarV1) vaccination status of children from present pregnancy was extracted at 24 months of age from Zhejiang provincial immunization information system (ZJIIS). Three variables was defined as the main outcomes, which included: (1) knowing about both the availability of VarV and the number of doses required; (2) positive attitude towards the utility of varicella vaccination; (3) the vaccination coverage of VarV1, which meant the proportion of children having received the VarV1. Counts and proportions were used to describe the socio-demographic characteristics of study participants, and their relationship with study outcomes were tested using chi-square tests in univariate analysis and logistic regression in multivariable analysis. Results: A total of 629 pregnant women participated in this study. The majority of the participants (68.0%) answered correctly about the transmission route of varicella. The proportion of participants who heard about varicella vaccination was 76.5% and 66.8% knew that VarV was currently available. Only 13.5% of the participants answered correctly that the complete VarV series needed two doses. Age, immigration status, education level, household income, and number of children of the pregnant women were significant predictors of the KAP regarding the VarV vaccination. Conclusions: The current survey indicated that optimal KAP levels and coverage on VarV vaccination were observed in three districts of Zhejiang Province. Health education programs on varicella and VarV vaccination directed towards both pre-natal and post-natal women are needed, which will result in a better attitude on vaccination of VarV and in a high coverage of VarV.

Relationship between receipt of substitutable for-fee vaccines and completion of the expanded programme on immunisation: a cross-sectional study in Fujian, China

OBJECTIVE

The aim of this study was to evaluate the relationship between receipt of the substitutable-for-fee vaccines (SFV) and completion of the expanded programme on immunisation (EPI).

DESIGN AND SETTINGS

A cross-sectional study was conducted in Fujian province, China.

PARTICIPANTS

Children who were born from 1 September 2009 to 31 August 2011, and who had been residing in the township for at least 3 months, were randomly recruited from 34 townships.

MAIN OUTCOMES MEASURES

Outcomes were completion rate of the EPI and coverage rate of the SFV.

RESULTS

The study included 1428 children, of whom 1350 (94.5%) finished the EPI and 282 (19.7%) received at least one dose of the SFV. Administration of the SFV was associated with an increased likelihood of completing the EPI (OR=3.2, 95% CI 1.3 to 7.6 in the total sample and OR=4.0, 95% CI 1.7 to 9.6 in the subsample of children in regions with the SFV accessibility). The impact of the SFV administration on completion of the EPI was larger among children whose parents have junior school education or less (97.8% and 97.9% vs 92.5% and 91.9%, both p<0.001) and among those with a timely hepatitis B vaccine first dose (98.5% vs 94.0%, p<0.001).

CONCLUSIONS

Receipt of SFV is associated with increased likelihood of completion of the EPI in Fujian, China.

The varicella vaccination pattern among children under 5 years old in selected areas in China

BACKGROUND

Vaccine is the most effective way to protect susceptible children from varicella. Few published literature or reports on varicella vaccination of Chinese children exist. Thus, in order to obtain specific information on varicella vaccination of this population, we conducted this survey.

METHODOLOGY

We first used purposive sampling methods to select 6 provinces 10 counties from eastern, middle and western parts of China with high quality of Immunization Information Management System (IIMS), and then randomly select children from population in the IIMS, then we checked vaccination certificate on-site.

PRINCIPAL FINDINGS

Based on the varicella vaccination information collected from 481 children's vaccination certificates from all ten selected counties in China, overall coverage of the first dose of varicella vaccine was 73.6%. There is a positive linear correlation between per capita GDP and vaccine coverage at county level (r=0.929, P < 0.01). The cumulative vaccine coverage among children at 1 year, 2 years and ≥3 years old were 67.6%, 71.9% and 73.6% respectively (X2=4.53, P =0.10). The age of vaccination was mainly concentrated in 12-17 months.

CONCLUSIONS

The coverage rate of the first dose of varicella vaccine in selected areas was lower than that recommended by WHO position paper. The coverage rate was relatively low in areas of low social-economic status. The cumulative coverage had no significant statistical difference among different age group. Most children received varicella vaccine before 3 years old. We suggest introducing the varicella vaccine into routine immunization program, to ensure universal high coverage among children in China. We also suggest that varicella vaccination information should be checked before entering school, in order to control and prevent varicella outbreaks in schools.

Determinants of inequality in the up-to-date fully immunization coverage among children aged 24-35 months: Evidence from Zhejiang province, East China

OBJECTIVE

This study aimed to determine the degree and determinants of inequality in up-to-date fully immunization (UTDFI) coverage among children of Zhejiang province, east China.

METHOD

We used data from the Zhejiang provincial vaccination coverage survey of 2014 and the health outcome was the UTDFI status among children aged 24-35 months. The household income per month was used as an index of socio-economic status for the inequality analysis. The concentration index (CI) was used to quantify the degree of inequality and the decomposition approach was applied to quantify the contributions from demographic factors to inequality in UTDFI coverage.

RESULTS

The UTDFI coverage was 80.63% and the CI for UTDFI coverage was 0.12028 (95% CI: 0.10852-0.13175), indicating that immunization practice significantly favored children with relatively higher socio-economic status. The results of decomposition analysis suggested that 68.2% of the socio-economic inequality in UTDFI coverage should be explained by the mother's education level. Furthermore, factors such as birth order, ethnic group, maternal employment status, residence, immigration status, GDP per-capital and percentage of public health spending of the total health spending also could explain the disparity in UTDFI coverage.

CONCLUSION

There exists inequality in UTDFI coverage among the socio-economic disadvantage children. Health interventions of narrowing the socio-economic inequality in UTDFI coverage will benefit from being supplemented with strategies aimed at poverty and illiteracy reduction.

Auditing the Immunization Data Quality from Routine Reports in Shangyu District, East China

Objective: To evaluate the immunization data quality in Shangyu District, East China. Methods: An audit for immunization data for the year 2014 was conducted in 20 vaccination clinics of Shangyu District. The consistency of immunization data was estimated by verification factors (VFs), which was the proportion of vaccine doses reported as being administered that could be verified by written documentation at vaccination clinics. The quality of monitoring systems was evaluated using the quality index (QI). Results: The VFs of 20 vaccine doses ranged from 0.94 to 1.04 at the district level. The VFs for the 20 vaccination clinics ranged from 0.57 to 1.07. The VFs for Shangyu District was 0.98. The mean of total QI score of the 20 vaccination clinics was 80.32%. A significant correlation between the VFs of the 3rd dose of the diphtheria-tetanus-pertussis combined vaccine (DTP) and QI scores was observed at the vaccination clinic level. Conclusions: Deficiencies in data consistency and immunization reporting practice in Shangyu District were observed. Targeted measures are suggested to improve the quality of the immunization reporting system in vaccination clinics with poor data consistency.

An Evaluation of Voluntary Varicella Vaccination Coverage in Zhejiang Province, East China

Background: In 2014 a 2-doses varicella vaccine (VarV) schedule was recommended by the Zhejiang Provincial Center for Disease Control and Prevention. We aimed to assess the coverage of the 1st dose of VarV (VarV₁) and the 2nd dose of VarV (VarV₂) among children aged 2–6 years through the Zhejiang Provincial Immunization Information System (ZJIIS) and to explore the determinants associated with the VarV coverage. Methods: Children aged 2–6 years (born from 1 January 2009 to 31 December 2013) registered in ZJIIS were enrolled. Anonymized individual records of target children were extracted from the ZJIIS database on 1 January 2016, including their VarV and (measles-containing vaccine) MCV vaccination information. The VarV₁ and VarV₂ coverage rates were evaluated for each birth cohorts. The coverage of VarV also was estimated among strata defined by cities, gender and immigration status. We also evaluated the difference in coverage between VarV and MCV. Results: A total of 3,028,222 children aged 2–6 years were enrolled. The coverage of VarV₁ ranged from 84.8% to 87.9% in the 2009–2013 birth cohorts, while the coverage of VarV₂ increased from 31.8% for the 2009 birth cohort to 48.7% for the 2011 birth cohort. Higher coverage rates for both VarV₁ and VarV₂ were observed among resident children in relevant birth cohorts. The coverage rates of VarV₁ and VarV₂ were lower than those for the 1st and 2nd dose of MCV, which were above 95%. The proportion of children who were vaccinated with VarV₁ at the recommended age increased from 34.6% for the 2009 birth cohort to 75.2% for the 2013 birth cohort, while the proportion of children who were vaccinated with VarV₂ at the recommended age increased from 19.7% for the 2009 birth cohort to 48.7% for the 2011 birth cohort. Conclusions: Our study showed a rapid increasing VarV₂ coverage of children, indicating a growing acceptance of the 2-doses VarV schedule among children’s caregivers and physicians after the new recommendation released. We highlighted the necessity for a 2-doses VarV vaccination school-entry requirement to achieve the high coverage of >90% and to eliminate disparities in coverage among sub-populations. We also recommended continuous monitoring of the VarV coverage via ZJIIS over time.