Impact of immunization programs on 11 childhood vaccine-preventable diseases in China: 1950-2018

Global vaccine coverage and childhood survival estimates: 1990-2019

Objective

To quantify the association between reduction in child mortality and routine immunization across 204 countries and territories from 1990 to 2019.

Methods

We used child mortality and vaccine coverage data from the Global Burden of Disease Study. We used a modified child survival framework and applied a mixed-effects regression model to estimate the reduction in deaths in children younger than 5 years associated with eight vaccines.

Findings

Between 1990 and 2019, the diphtheria-tetanus-pertussis (DTP), measles, rotavirus and Haemophilus influenzae type b vaccines were significantly associated with an estimated 86.9 (95% confidence interval, CI: 57.2 to 132.4) million fewer deaths in children younger than 5 years worldwide. This decrease represented a 24.2% (95% CI: 19.8 to 28.9) reduction in deaths relative to a scenario without vaccines. The DTP and measles vaccines averted 46.7 (95% CI: 30.0 to 72.7) million and 37.9 (95% CI: 25.4 to 56.8) million deaths, respectively. Of the total reduction in child mortality associated with vaccines, 84.2% (95% CI: 83.0 to 85.1) occurred in 73 countries supported by Gavi, the Vaccine Alliance, with an estimated 45.4 (95% CI: 29.8 to 69.2) million fewer deaths from 2000 to 2019. The largest reductions in deaths associated with these four vaccines were in India, China, Ethiopia, Pakistan and Bangladesh (in order of the size of reduction).

Conclusion

Vaccines continue to reduce childhood mortality significantly, especially in Gavi-supported countries, emphasizing the need for increased investment in routine immunization programmes.

Advancing the National Immunization Program in an era of achieving universal vaccine coverage in China and beyond

BACKGROUND

Immunization is a cornerstone of public health. Despite great success, China's National Immunization Program (NIP) faces challenges, such as the integration of several World Health Organization-recommended vaccines and other systemic issues. The Innovation Laboratory for Vaccine Delivery Research (VaxLab), supported by the Bill & Melinda Gates Foundation and established in 2021 at Duke Kunshan University, focuses on enhancing China's NIP through research and policy advocacy. This editorial aims to summarize the key findings of the manuscripts published in the collection contributed by VaxLab team and set the future research agenda.

KEY FINDINGS

The collection contains eleven manuscripts discussing China's immunization landscape and strategies to improve coverage, particularly for non-NIP vaccines like human papillomavirus vaccine (HPV), pneumococcal conjugate vaccine (PCV), Haemophilus influenzae type b vaccine (Hib), and rotavirus vaccines. Key findings include: (i) The COVID-19 vaccination campaign demonstrated China's capacity for rapid, large-scale immunization efforts, suggesting potential for broader vaccine coverage improvements; (ii) Efforts in combating cervical cancer through the HPV vaccine indicate progress but also highlight challenges like vaccine supply and equitable access; (iii) The lag in adopting higher-valent paediatric combination vaccines in China needs attention to address regulatory and health system hurdles; (iv) Disparities in access to non-NIP vaccines underscore the need for government initiatives to improve vaccine coverage, especially for remote areas and marginalized populations; (v) Original studies emphasize the influence of caregivers' knowledge, health workers' financial incentives, and concerns about vaccine efficacy on immunization rates; (vi) Case studies from the Weifang City of China and Indonesia to introduce PCV offer insights on successful vaccine introduction strategies and the impact of innovative financing and government support.

CONCLUSION

The articles emphasize the need for government leadership, strategic policymaking, and public awareness to enhance vaccine coverage and equity. The VaxLab will continue strengthening China's NIP by focusing on vaccine financing, emphasizing diversity, equity, and inclusion, and improving maternal vaccination coverage. Research will extend to Southeast Asian and Western Pacific regions, especially in middle-income countries facing challenges in vaccine financing and delivery. The collective efforts outlined in this collection show a commitment to evolving and adapting immunization strategies to meet global health goals and to provide equitable access to vaccines for all.

The Effectiveness of National Expanded Program on Immunization With Hepatitis A Vaccines in the Chinese Mainland: Interrupted Time-Series Analysis

BACKGROUND

The high prevalence of hepatitis A delivered a blow to public health decades ago. The World Health Organization (WHO) set a goal to eliminate viral hepatitis including hepatitis A by 2030. In 2008, hepatitis A vaccines were integrated into the Expanded Program on Immunization (EPI) in China to alleviate the burden of hepatitis A, although the effectiveness of the EPI has not been well investigated.

OBJECTIVE

We aimed to evaluate the intervention effect at both provincial and national levels on the incidence of hepatitis A in the Chinese mainland from 2005 to 2019.

METHODS

Based on the monthly reported number of hepatitis A cases from 2005 to 2019 in each provincial-level administrative division, we adopted generalized additive models with an interrupted time-series design to estimate province-specific effects of the EPI on the incidence of hepatitis A among the target population (children aged 2-9 years) from 2005 to 2019. We then pooled province-specific effect estimates using random-effects meta-analyses. We also assessed the effect among the nontarget population and the whole population.

RESULTS

A total of 98,275 hepatitis A cases among children aged 2-9 years were reported in the Chinese mainland from 2005 to 2019, with an average annual incidence of 5.33 cases per 100,000 persons. Nationally, the EPI decreased the hepatitis A incidence by 80.77% (excess risk [ER] -80.77%, 95% CI -85.86% to -72.92%) during the study period, guarding an annual average of 28.52 (95% empirical CI [eCI] 27.37-29.00) cases per 100,000 persons among the target children against hepatitis A. Western China saw a more significant effect of the EPI on the decrease in the incidence of hepatitis A among the target children. A greater number of target children were protected from onset in Northwest and Southwest China, with an excess incidence rate of -129.72 (95% eCI -135.67 to -117.86) and -66.61 (95% eCI -67.63 to -64.22) cases per 100,000 persons on average, respectively. Intervention effects among nontarget (ER -32.88%, 95% CI -39.76% to -25.21%) and whole populations (ER -31.97%, 95% CI -39.61% to -23.37%) were relatively small.

CONCLUSIONS

The EPI has presented a lasting positive effect on the containment of hepatitis A in the target population in China. The EPI's effect on the target children also provided a degree of indirect protection for unvaccinated individuals. The continuous surveillance of hepatitis A and the maintenance of mass vaccination should shore up the accomplishment in the decline of hepatitis A incidence to ultimately achieve the goal set by the WHO.

Promoting higher-valent pediatric combination vaccines in China: challenges and recommendations for action

Many countries have adopted higher-valent pediatric combination vaccines to simplify vaccination schedules and minimize health expenditures and social costs. However, China is conservative in the use of pediatric combination vaccines. By reviewing and synthesizing quantitative and qualitative data, in this commentary we identify gaps and challenges to combination vaccine use and make recommendations for promoting use of higher-valent pediatric combination vaccines in China. Challenges are in four dimensions: (1) legislation and regulation, (2) immunization schedule design, (3) vaccine awareness and price, and (4) research and development capacity. To optimize the use of combination vaccines to reduce vaccine-preventable disease burden, we make recommendations that address key challenges: (1) develop policies and regulations to strengthen enforcement of the Vaccine Administration Law and remove regulatory hurdles that hinder combination vaccine research and development, (2) establish an evidence-informed policy-making mechanism for combination vaccines, (3) resolve immunization schedule conflicts between monovalent and combination vaccines, and (4) implement effective interventions to increase vaccine awareness and reduce price.

How to address vaccine hesitancy? Lessons from National Hepatitis B Immunization Program in China

China, with the severe burden of hepatitis B, plays a significant role in the global efforts towards eliminating hepatitis B disease by 2030. Vaccination is recognized as the most effective measure to prevent infectious diseases. However, vaccine hesitancy remains a significant barrier to achieving herd immunity across diverse populations. To address this issue, the health ministries and public health authorities in China have implemented various measures to encourage hepatitis B vaccination. China's National Hepatitis B Immunization Program, initiated in 1985, has been successful in controlling this vaccine-preventable disease. Given the challenges in eliminating hepatitis B, strengthening the National Hepatitis Immunization Program in China is of utmost importance. Through an analysis of policy documents, reports, and scientific papers, the history of the program was summarized, and effective approaches to address vaccine hesitancy were identified. This will help achieve universal health coverage of vaccines and effectively work towards meeting the goals set for 2030.

Construction of an indicator framework for vaccine inclusion in public health programs: A Delphi-entropy method study

Governments must decide which vaccine priority to include in their public health programs. Using the modified Delphi and entropy method, we developed an indicator framework for vaccine inclusion at the national, provincial, municipal, and district/county levels, each containing three dimensions. In total, 4 primary indicators, 17 secondary indicators, and 45 tertiary indicators were selected, covering vaccine-preventable diseases, candidate vaccines, and social drivers of the supply and demand sides. From a subjective perspective, there was no significant weighting difference in the primary and secondary indicators at all administrative levels. "Vaccine-preventable diseases" as a primary indicator had the greatest weight in the peer group, of which "Health burden" had the highest weight among the secondary indicators. From the objective perspective, the social drivers on the supply and demand sides of the primary indicators accounted for 65% and higher. Among the secondary indicators, "the characteristics of the candidate vaccine" and "vaccine-related policies on the supply side" held 8% of weights or more at both national and provincial levels. "Demographic characteristics" held the highest weight at the municipal (13.50) and district/county (15.45) level. This study indicates that China needs different considerations when using WHO-recommended vaccines at the national, provincial, municipal, and district/county levels. In addition, this study highlights that behavioral and social drivers are important indicators that need to be considered for decision-making. This framework provides a tool for policymakers to determine the inclusion priority of candidate vaccines.

Prevalence and factors associated with pentavalent vaccination: a cross-sectional study in Southern China

BACKGROUND

Immunization is one of the most far-reaching and cost-effective strategies for promoting good health and saving lives. A complex immunization schedule, however, may be burdensome to parents and lead to reduced vaccine compliance and completion. Thus, it is critical to develop combination vaccines to reduce the number of injections and simplify the immunization schedule. This study aimed to investigate the current status of the pentavalent diphtheria-tetanus-acellular pertussis inactivated poliomyelitis and Haemophilus influenzae type B conjugate (DTaP-IPV/Hib) vaccination in Southern China as well as explore the factors in the general population associated with uptake and the differences between urban and rural populations.

METHODS

A cross-sectional study was conducted with recently enrolled kindergarten students in Hainan Province between December 2022 and January 2023. The study employed a stratified multistage cluster random sampling method. Information regarding the demographic characteristics and factors that influence decisions were collected from the caregivers of children via an online questionnaire. Multivariate logistic regression was used to determine the factors associated with the status of DTap-IPV/Hib vaccinations.

RESULTS

Of the 4818 valid responses, 95.3% of children were aged 3-4 years, and 2856 (59.3%) held rural hukou. Coverage rates of the DTaP-IPV/Hib vaccine, from 1 to 4 doses, were 24.4%, 20.7%, 18.5%, and 16.0%, respectively. Caregivers who are concerned about vaccine efficacy [adjusted odds ratio (aOR) = 1.53, 95% confidence interval (CI): 1.30-1.79], the manufacturer (aOR = 2.05, 95% CI: 1.69-2.49), and a simple immunization schedule (aOR = 1.26, 95% CI: 1.04-1.54) are factors associated with a higher likelihood of vaccinating children against DTaP-IPV/Hib. In addition, caregivers in urban areas showed more concern about the vaccine price (P = 0.010) and immunization schedule (P = 0.022) in regard to vaccinating children.

CONCLUSIONS

The DTaP-IPV/Hib vaccine coverage rate in Hainan Province remains low. Factors such as lower socioeconomic status, cultural beliefs, concerns about vaccine safety, and cost may hinder caregivers from vaccinating their children. Further measures, such as health education campaigns to raise knowledge and awareness, and encouragement of domestic vaccine innovation, which would reduce out-of-pocket costs, could be implemented to improve the coverage of DTap-IPV/Hib vaccination.

Annual incidence and fatality rates of notifiable infectious diseases in southeast China from 1950 to 2022 and relationship to socioeconomic development

Background

Over the past 70 years, China has advanced significantly in the prevention and treatment of infectious diseases while simultaneously undergoing a socioeconomic transformation, making it a useful source of data for analysing relationships between public health policy and the control of infectious diseases.

Methods

We collected data on the incidence of notifiable infectious diseases and associated fatalities in Jiangsu province in southeast China from the Provincial Center for Disease Control and Prevention, Provincial Institute of Parasitic Diseases, and the Nationwide Notifiable Infectious Diseases Reporting Information System. We compared data from different historical periods using descriptive statistical methods, joinpoint regression, and correlation analysis.

Results

During 1950-2022, 75 754 008 cases of 46 notifiable infectious diseases were reported in Jiangsu, with an average annual incidence was 1679.49 per 100 000 population and a fatality rate of 1.82 per 1000 persons. The incidence of classes A-B decreased (average annual percent change (AAPC) = -2.1) during the entire study period, while the incidence of class C increased (AAPC = 10.8) after 2004. The incidence of intestinal diseases (AAPC = -4.4) and vector-borne and zoonotic diseases (AAPC = -8.1) decreased rapidly, while the incidence of sexually transmitted and blood-borne diseases (AAPC = 1.8) increased. The number of medical and health institutions and the per capita gross domestic product correlated negatively with the annual incidence of diseases in classes A-B, but not with fatality rates.

Conclusions

Although the annual incidence of many severe infectious diseases has decreased in Jiangsu since 1950, the incidence of sexually transmitted and blood-borne diseases increased. Socioeconomic growth and sustainable investment in health systems are associated with better control of infectious diseases.

The relation between digital literacy, cyberchondria, and parents' attitudes to childhood vaccines

PURPOSE

This study aimed to examine the relationship between digital literacy, cyberchondria and parents' hesitancy about childhood vaccines.

DESIGN AND METHODS

The study was cross-sectional, and parents with children aged 3-5 years who had access to the questionnaire were sent online and volunteered to participate.

RESULTS

The total mean score of the Parents' Attitude to Childhood Vaccines Scale was 44.89 ± 14.99, 31.3% of the parents were hesitant about childhood vaccines. Parental hesitancy about childhood vaccinations was 3.26 times (95% CI, 1.56-6.81) for single participants and 2.77 times (95% CI, 1.33-5.74) for the participants with a high school diploma than primary school graduates, 4.69 times for the participants who did not have a healthcare professional in their family (95% CI, 2.08-10.59), 16.02 times (95% CI, 6.61-10.80) for the participants who did not have a full round of vaccines, 1.81 times higher (95% CI, 1.13-2.88) than the participants who did not have enough information about vaccines. Hesitancy increased as the cyberchondria severity score increased (95% CI, 1.02-1.09), and digital literacy decreased (95% CI, 0.34-0.87).

CONCLUSIONS

One-third of the parents had hesitations about childhood vaccines. Vaccine hesitancy is affected negatively by digital literacy and positively by cyberchondria.

PRACTICE IMPLICATION

Meeting parents' accurate and reliable vaccine information will positively affect their attitudes and behaviours. Therefore, the level of cyberchondria among parents should be reduced, and their digital literacy should be increased.

Coverage and Equity of Childhood Vaccines in China

IMPORTANCE

Measuring vaccination coverage rates and equity is crucial for informing immunization policies in China.

OBJECTIVES

To estimate coverage rates and multidimensional equity for childhood vaccination in China.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study was conducted via a survey in 10 Chinese provinces between August 5 and October 16, 2019, among children ages 6 months to 5 years and their primary caregivers. Children's vaccination records and their primary caregivers' demographics and socioeconomic status were collected. Data were analyzed from November 2019 to March 2022.

MAIN OUTCOMES AND MEASURES

Vaccine coverage rates were measured as a percentage of National Immunization Program (NIP) and non-NIP vaccines administered before the day on which the child was surveyed. A multidimensional equity model applied a standardized approach to ranking individuals from least to most unfairly disadvantaged by estimating differences between observed vaccination status and estimated vaccination status as function of fair and unfair variation. Fair sources of variation in coverage included whether the child was of age to receive the vaccine, and unfair sources of variation included sex of the child and sociodemographic characteristics of caregivers. Absolute equity gaps (AEGs), concentration index values, and decompositions of factors associated with vaccine equity were estimated in the model.

RESULTS

Vaccine records and sociodemographic information of 5294 children (2976 [52.8%] boys and 2498 [47.2%] girls; age range, 6-59 months; 1547 children aged 12-23 months) and their primary caregivers were collected from 10 provinces. Fully immunized coverage under the NIP was 83.1% (95% CI, 82.0%-84.1%) at the national level and more than 80% in 7 provinces (province coverage ranged from 77.8% [95% CI, 74.3% to 81.3%] in Jiangxi to 88.4% [95% CI, 85.7%-91.1%] in Beijing). For most non-NIP vaccines, however, coverage rates were less than 50%, ranging from 1.8% (95% CI, 1.3%-2.2%) for the third dose of rotavirus vaccine to 67.1% (65.4% to 68.8%) for the first dose of the varicella vaccine. The first dose of Haemophilus influenzae type b vaccine had the largest AEG, at 0.603 (95% CI, 0.570-0.636), and rotavirus vaccine dose 3 had the largest concentration index value, at 0.769 (95% CI, 0.709-0.829). The largest share of non-NIP vaccine inequity was contributed by monthly family income per capita, followed by education level, place of residence, and province for caregivers. For example, the proportion of explained inequity for pneumococcal conjugate vaccine dose 3 was 40.94% (95% CI, 39.49%-42.39%), 22.67% (95% CI, 21.43%-23.9%), 27.15% (95% CI, 25.84%-28.46%), and 0.68% (95% CI, 0.44%-0.92%) for these factors, respectively.

CONCLUSIONS AND RELEVANCE

This cross-sectional study found that NIP vaccination coverage in China was high but there was inequity for non-NIP vaccines. These findings suggest that improvements in equitable coverage of non-NIP vaccination may be urgently needed to meet national immunization goals.

Developing an effective and sustainable national immunisation programme in China: issues and challenges

Since its establishment in 1978, China's National Immunization Program has made remarkable achievements in the control of vaccine-preventable diseases. The National Immunization Program is a vertically integrated programme in the health system, which delivers immunisation services to children. However, achieving the ambitious goals of the Immunization Agenda 2030 and Healthy China 2030 will require overcoming challenges to the National Immunization Program's future expansion and development. Key challenges include inclusion of all WHO-recommended vaccines into the routine programme, improving the function and support of the National Immunization Advisory Committee, increasing and sustaining reliable vaccination financing, ensuring uninterrupted vaccine supplies, overcoming regional disparities in immunisation practices and cold chain processes, strengthening the workforce, and integrating immunisation information systems into all aspects of the programme. It is crucially important to strengthen the National Immunization Program to attain universal coverage of life-saving vaccines in China and meet the 2030 goals.

Automatic Identification of MALDI-TOF MS Database Using Classical Bordetella Species Isolates

Objective

To evaluate and expand the automatic identification and clustering of clinical Bordetella species by MALDI-TOF MS.

Methods

Twenty-eight field isolated strains, identified by whole-gene sequencing analysis, were analyzed by MALDI-TOF MS, and the spectra obtained were used to replenish the internal database of the manufacturer. To evaluate and expand the robustness of the database, MALDI-TOF MS identified 91 clinical isolates (except those used for implementation). A distance tree based on mass spectrometry data is constructed to confirm similarity and clusters of each clinical Bordetella species by using the MALDI Biotyper 3.1 software.

Results

In this research, when we used the implemented Bruker Daltonics database in our laboratory, 91 clinical isolates were identified at the genus level (100%) and 93.4% were identified at the species level (85/91). We performed proteomics analysis and divided these 91 isolates into cluster I (2.2%) and cluster II (97.8%). The largest group is cluster II (n = 89 isolates), which has been divided into two subclusters. Trees created by analyzing the protein mass spectra of the three species of the clinical isolates reflected their classification.

Conclusion

MALDI-TOF MS may present an attractive alternative to automatically confirm and cluster the fastidious bacteria difficult to culture. Extension of identification of the MALDI-TOF MS database is viably fast, more efficient, and alternative to conventional methods in confirming the classical Bordetella species. This strategy could promote the epidemiological and taxonomic research of this important pathogen.

Cost-Effectiveness of Three Poliovirus Immunization Schedules in Shanghai, China

In Shanghai, China, a polio immunization schedule of four inactivated polio vaccines (IPV) has been implemented since 2020, replacing the schedules of a combination of two IPVs and two bivalent live attenuated oral polio vaccines (bOPV), and four trivalent live attenuated oral polio vaccines (tOPV). This study aimed to assess the cost-effectiveness of these three schedules in infants born in 2016, in preventing vaccine-associated paralytic poliomyelitis (VAPP). We performed a decision tree model and estimated incremental cost-effectiveness ratio (ICER). Compared to the four-tOPV schedule, the two-IPV-two-bOPV schedule averted 1.2 VAPP cases and 16.83 disability-adjusted life years (DALY) annually; while the four-IPV schedule averted 1.35 VAPP cases and 18.96 DALY annually. Consequently, ICER_VAPP and ICER_DALY were substantially high for two-IPV-two-bOPV (CNY 12.96 million and 0.93 million), and four-IPV (CNY 21.24 million and 1.52 million). Moreover, net monetary benefit of the two-IPV-two-bOPV and four-IPV schedules was highest when the cost of IPV was hypothesized to be less than CNY 23.75 or CNY 9.11, respectively, and willingness-to-pay was hypothesized as CNY 0.6 million in averting one VAPP-induced DALY. IPV-containing schedules are currently cost-ineffective in Shanghai. They may be cost-effective by reducing the prices of IPV, which may accelerate polio eradication in Chinese settings.