Vaccination coverage estimates and utilization patterns of inactivated enterovirus 71 vaccine post vaccine introduction in Ningbo, China

Epidemiological characteristics of 5838 cases of enterovirus infection in children in Hangzhou from 2018 to 2023

This study retrospectively explored the characteristics of 5838 children with enterovirus infection in our hospital from 2018 to 2023. In addition, children with enterovirus (EV: EV typing was performed using RT-PCR) infection exhibiting clinical manifestations of viral encephalitis were investigated. Pharyngeal swabs or fecal samples from outpatients and inpatients from our hospital were collected from 2018 to 2023 and were subjected to EV nucleic acid detection using real-time fluorescence quantitative PCR. Furthermore, cerebrospinal fluid EV nucleic acid detection was performed for children with clinical manifestations of viral encephalitis. Descriptive epidemiological methods were used to analyze the age, sex, and etiology of EV infection cases. Statistical analyses were performed with SPSS 20.0. The statistical data were expressed as percentages, and the χ2 test was used for statistical analysis. A total of 9676 children were included in this study, and 5838 (60.33%) showed positive EV nucleic acid test results. These included 1909 cases of Coxsackievirus group A type 6 (CV-A6) (32.70%), 259 cases of Coxsackievirus group A type 16 (CV-A16) (4.44%), 252 cases of Coxsackievirus group A type 10 (CV-A10) (4.32%), and 34 cases of enterovirus type 71 (EV-A71) (0.58%). A total of 3384 other uncategorized EVs (57.97%) were found. The detection rates of EV-A71 and CV-A16 decreased year by year, while the detection rates of other EV nucleic acids increased year by year. Cerebrospinal fluid (CSF) EV nucleic acid detection was performed on 1520 children with positive EV nucleic acid throat swabs or stool samples showing clinical manifestations of viral encephalitis; a total of 140 positive cases (9.21%) were detected, including CV-A16 2.14% (3/140), CV-A10 1.43% (2/140), CV-A6 9.29% (13/140), EV-A71 0%(0/140), and other uncategorized EVs 87.14% (122/140). Among the 140 cerebrospinal fluid EV-positive children, 32 had typical hand-foot-mouth disease or herpetic angina, and 108 had only fever and upper respiratory tract infection. Real-time fluorescence quantitative PCR detection and virus typing can greatly improve the diagnosis rate of EV. Multi-sample EV nucleic acid detection and virus typing in children with viral encephalitis effectively improve the etiological diagnosis rate. Nonetheless, the development of multivalent vaccines remains the most economical and effective measure to prevent and control EV infection.

Safety of an inactivated enterovirus 71 vaccine administered concurrently with other vaccines among infants aged 6-11 months: An observational study using active surveillance

Vaccine co-administration can efficiently increase vaccination uptake and timely immunization. This study aimed to evaluate the safety of the enterovirus 71 (EV71) vaccine administered alone or concurrently with other vaccines in infants 6-11 months. A total of 3,769 EV71 vaccine doses were administered to children in the active surveillance area, of which 1,909 were administered concurrently with other vaccines and 1,860 doses were administered alone. Active surveillance was conducted to observe adverse events (AEs) within 0-7 and ≥8 days after vaccination and to determine the incidence of reported AEs. The overall AE incidence was 2.12% (95% CI: 1.66%-2.58%), with 1.56% (95% CI:1.00%-2.12%) for the EV71 vaccine alone and 2.67% (95% CI: 1.95%-3.40%) for simultaneous administration of the EV71 vaccine and other vaccines (x 2  = 5.612, p = .018). The solicited local AE incidence was 1.00% (95% CI: 0.55%-1.44%) in the EV71 vaccine co-administration group and 0.59% (95% CI: 0.24%-0.94%) in the EV71 vaccine alone group (x 2  = 1.946, p = .018). The solicited systemic AE incidence was 1.68% (95% CI: 1.10%-2.25%) and 0.86% (95% CI: 0.44%-1.28%) in the EV71 vaccine co-administered and EV71 vaccine alone groups, respectively (x 2  = 4.990, p = .025). No serious vaccine-related AEs were reported. Fever was the most common AE; no difference was observed in the incidence rate of fever between the two groups (x 2  = 3.467, p = .063). Overall, AE incidence following EV71 vaccination alone or concurrently with other vaccines was acceptable; concurrent vaccination did not increase AE risk or severity.

Exploring the spatiotemporal effects of meteorological factors on hand, foot and mouth disease: a multiscale geographically and temporally weighted regression study

The influence of meteorological factors on hand, foot, and mouth disease (HFMD) is not on the same scale, it's rare for previous studies to measure and recognize the independent regression relationship between each variable in space and time scale. This study used a multiscale geographically and temporally weighted regression (MGTWR) model to explore the relationship between the incidence of HFMD and related meteorological factors in Shandong Province, China, during 2015-2019 and attempted to quantify the influence of meteorological factors on HFMD under different spatiotemporal effects. Meanwhile, we used the Global Moran's I statistic and Local Moran's I statistic to test the spatial autocorrelation of the incidence of HFMD. HFMD had spatial autocorrelation at the county level in Shandong Province. The MGTWR model outperformed the OLS and GTWR models in determining the relationship between meteorological factors and HFMD. The study highlights significant spatiotemporal non-stationarity in the relationship between meteorological factors and HFMD. Temperature was predominantly positively correlated with HFMD, especially in the peninsula region during spring and summer. Humidity exhibited a predominantly positive correlation, especially in the Shandong Peninsula. Precipitation also showed a positive correlation with HFMD, particularly in western regions and during the winter months. Wind speed had a predominantly negative correlation with HFMD in the central and southwestern regions. The results might help public health authorities set priorities for targeted prevention and control measures in different regions and weather conditions, and provide guidance for the government to rationally allocate public health resources.

A multiplex one-step fluorescence quantitative differential diagnosis method for severe hand, foot and mouth disease caused by coxsackievirus A16

Hand foot and mouth disease (HFMD) is a common childhood infectious disease which is caused by human enterovirus. The objective of this study was to develop a rapid, sensitive, and accurate method for detecting severe HFMD caused by coxsackievirus A16 (CV-A16). A closed-tube sensitive multiplex one-step reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR) was applied to detect CV-A16 in the early stage of severe HFMD. This assay targeted the CV-A16 structure protein VP1 to distinguish CV-A16 from other coxsackieviruses The 5'UTR region of enteric viruses was used for detecting the enterovirus and ribonuclease P (RNaseP) was adopted as the internal reference gene. The multiplex MGB probe assay system was used to detect PCR amplicons with different fluorescence reporters in the same system. The limit of detection (LOD) of the RT-qPCR assay for the CV-A16 VP1 gene was 125.893 copies/μl, for the 5' UTR was 50.1187 copies/μl and for the RNaseP gene was 158.49 copies/μl. Furthermore, specificity analysis showed that the multiplex RT-PCR had no cross-reactivity with the influenza virus, herpangina virus and SARS-COV-2. In correlation analysis, the sensitivity of the multiplex RT-qPCR assay for CV-A16 detection was 100 % (288/288) and the specificity of the multiplex RT-qPCR assay was 99.94 % (3395/3397). The overall agreement between the multiplex RT-qPCR and the results of clinical diagnosis was 99.95 % (3683/3685) and kappa value was 0.996 (p<0.001). The entire procedure, from specimen processing to result reporting, could be completed within 1.5 hours. The one-step multiplex RT-qPCR assay for detecting CV-A16 developed in this study is a good laboratory diagnostic tool for rapid and reliable distinguished detection of CV-A16, especially for severe HFMD patients at an early stage in the disease with low virus load of CV-A16.

Analysis of the Impact of Inactivated A71 Vaccine on the Incidence of Hand-Foot-Mouth Disease in Pudong New Area, Shanghai

The aim of this study was to investigate the level of inactivated A71 (EV-A71) vaccination in Pudong New Area of Shanghai and its effects on the epidemiology and pathogen spectrum of hand-foot-mouth disease (HFMD) in this area, as well as to provide a basis for improving the prevention and control strategy of HFMD in this area. Data were collected from the "Comprehensive Management Cloud Platform for Immunization Program" system from December 2016 to December 2022. The data on HFMD cases from January 2012 to December 2022 were extracted from the "China Information System for Disease Control and Prevention". A total of 484,056 doses were administered. The vaccination rate of the first dose was 14.03%, and the full vaccination rate was 13.33%. There were significant differences between the first dose and the full vaccination rate in different years (χ2 = 46,538.831, p < 0.001, χ2 = 50,013.946, p < 0.001). A total of 91625 cases of HFMD were reported, including 58 severe cases, and no deaths. Before and after the administration of the inactivated EV-A71 vaccine, there were statistical differences in the distribution of HFMD cases in terms of gender, household registration, occupation, and age (p < 0.001). The etiological surveillance results showed that the rate of enterovirus positivity was 84.15%, with 9.85% being EV-A71, 23.74% CV-A16, and 50.56% non-EV-A71 and non-CV-A16. The coverage rate of the inactivated EV-A71 vaccine in Pudong New Area was not high, and the incidence of HFMD showed a downward trend after the postmarketing of the vaccine. The majority of HFMD infections were non-EV-A71 and non-CV-A16, with CV-A6 accounting for the highest proportion. It is recommended to accelerate the development of combined vaccines to provide more antibody protection.

Spatiotemporal Changes and Influencing Factors of Hand, Foot, and Mouth Disease in Guangzhou, China, From 2013 to 2022: Retrospective Analysis

Background

In the past 10 years, the number of hand, foot, and mouth disease (HFMD) cases reported in Guangzhou, China, has averaged about 60,000 per year. It is necessary to conduct an in-depth analysis to understand the epidemiological pattern and related influencing factors of HFMD in this region.

Objective

This study aims to describe the epidemiological characteristics and spatiotemporal distribution of HFMD cases in Guangzhou from 2013 to 2022 and explore the relationship between sociodemographic factors and HFMD incidence.

Methods

The data of HFMD cases in Guangzhou come from the Infectious Disease Information Management System of the Guangzhou Center for Disease Control and Prevention. Spatial analysis and space-time scan statistics were used to visualize the spatiotemporal distribution of HFMD cases. Multifactor ordinary minimum regression model, geographically weighted regression, and geographically and temporally weighted regression were used to analyze the influencing factors, including population, economy, education, and medical care.

Results

From 2013 to 2022, a total of 599,353 HFMD cases were reported in Guangzhou, with an average annual incidence rate of 403.62/100,000. Children aged 5 years and younger accounted for 93.64% (561,218/599,353) of all cases. HFMD cases showed obvious bimodal distribution characteristics, with the peak period from May to July and the secondary peak period from August to October. HFMDs in Guangzhou exhibited a spatial aggregation trend, with the central urban area showing a pattern of low-low aggregation and the peripheral urban area demonstrating high-high aggregation. High-risk areas showed a dynamic trend of shifting from the west to the east of peripheral urban areas, with coverage first increasing and then decreasing. The geographically and temporally weighted regression model results indicated that population density (β=-0.016) and average annual income of employees (β=-0.007) were protective factors for HFMD incidence, while the average number of students in each primary school (β=1.416) and kindergarten (β=0.412) was a risk factor.

Conclusions

HFMD cases in Guangzhou were mainly infants and young children, and there were obvious differences in time and space. HFMD is highly prevalent in summer and autumn, and peripheral urban areas were identified as high-risk areas. Improving the economic level of peripheral urban areas and reducing the number of students in preschool education institutions are key strategies to controlling HFMD.

Chinese parents' intention to vaccinate their 0-5-year-old children with the EV-71 vaccine against hand, foot, and mouth disease and willingness-to-pay

Background

This study aimed to determine the intention and willingness-to-pay (WTP) of Chinese parents/guardians to vaccinate their children with the EV-71 vaccine. Knowledge levels about hand, foot, and mouth disease (HFMD) and the EV-71 vaccine were also investigated.

Methods

A cross-sectional, self-administered online survey was conducted between November 2022 and March 2023. A stratified multi-stage random sampling method was used to recruit parents/guardians of children aged 0-5 years in southeastern China.

Results

A total of 3,626 complete responses were received. The mean knowledge score of HFMD was 9.99 (±4.23) out of a total of 14 points. The majority of the participants reported a somewhat willing intent (58.8%), followed by an extremely willing intent (28.9%). Participants who did not consider the EV-71 vaccine expensive (OR = 2.94, 95%CI 2.45-3.53) perceived that the EV-71 vaccine is effective (OR = 2.73, 95%CI 1.52-4.90), and a high knowledge level of HFMD (OR = 1.90, 95%CI 1.57-2.29) had the highest significant odds of having an extremely willing intent to vaccinate their children with the EV-71 vaccine. The median (interquartile range [IQR]) of WTP for the EV-71 vaccine was CNY¥200/USD$28 (IQR CNY¥100-400/USD$14-56). The highest marginal WTP for the vaccine was mainly influenced by the perceived high cost of the vaccine. Those participants who did not consider the EV-71 vaccine expensive had more than 10 times higher odds of vaccinating their children (OR = 10.86, 95%CI 8.49-13.88). Perceived susceptibility, perceived benefits, and perceived barriers were also significant influencing factors in the highest marginal WTP.

Conclusion

The findings demonstrate the importance of improving health promotion and reducing the barriers to EV-71 vaccination. Therefore, it is important to improve health promotion and reduce the barriers to EV-71 vaccination.

Phase I, Single-Dose Study to Assess the Pharmacokinetics and Safety of Suramin in Healthy Chinese Volunteers

Purpose

Suramin is a multifunctional molecule with a wide range of potential applications, including parasitic and viral diseases, as well as cancer.

Methods

A double-blinded, randomized, placebo-controlled single ascending dose study was conducted to investigate the safety, tolerability, and pharmacokinetics of suramin in healthy Chinese volunteers. A total of 36 healthy subjects were enrolled. All doses of suramin sodium and placebo were administered as a 30-minute infusion. Blood and urine samples were collected at the designated time points for pharmacokinetic analysis. Safety was assessed by clinical examinations and adverse events.

Results

After a single dose, suramin maximum plasma concentration (C_max) and area under the plasma concentration-time curve from time zero to the time of the last measurable concentration (AUC_last) increased in a dose-proportional manner. The plasma half-life (t_1/2) was dose-independent, average 48 days (range 28-105 days). The cumulative percentages of the dose excreted in urine over 7 days were less than 4%. Suramin can be detected in urine samples for longer periods (more than 140 days following infusion). Suramin was generally well tolerated. Treatment-emergent adverse events (TEAEs) were generally mild in severity.

Conclusion

The PK and safety profiles of suramin in Chinese subjects indicated that 10 mg/kg or 15 mg/kg could be an appropriate dose in a future multiple-dose study.

A guideline for economic evaluations of vaccines and immunization programs in China

This study aimed to develop a consensus framework for economic evaluations of vaccines as a national guideline in China. Some unique and important aspects were particularly emphasized. Nineteen Chinese experts in the field of health economics and immunization decision-making were nominated to select and discuss relevant aspects of vaccine economic evaluations in China. A workshop attended by external experts was held to summarize unique and important aspects and formulate consensus recommendations. There were ten unique and/or important aspects identified for economic evaluations of vaccines in China, including study perspectives, comparator strategies, analysis types, model choices, costing approaches, utility measures, discounting, uncertainty, equity, and evaluation purposes. Background information and expert recommendations were provided for each aspect. Economic evaluations of vaccines should play an important role in China's immunization policy-making. This guideline can help improve the quality of economic evaluations as a good practice consensus.

Study on the interaction between different pathogens of Hand, foot and mouth disease in five regions of China

Objectives

This study aims to explore the interaction of different pathogens in Hand, foot and mouth disease (HFMD) by using a mathematical epidemiological model and the reported data in five regions of China.

Methods

A cross-regional dataset of reported HFMD cases was built from four provinces (Fujian Province, Jiangsu province, Hunan Province, and Jilin Province) and one municipality (Chongqing Municipality) in China. The subtypes of the pathogens of HFMD, including Coxsackievirus A16 (CV-A16), enteroviruses A71 (EV-A71), and other enteroviruses (Others), were included in the data. A mathematical model was developed to fit the data. The effective reproduction number (R _eff ) was calculated to quantify the transmissibility of the pathogens.

Results

In total, 3,336,482 HFMD cases were collected in the five regions. In Fujian Province, the R _eff between CV-A16 and EV-A71&CV-A16, and between CV-A16 and CV-A16&Others showed statistically significant differences (P < 0.05). In Jiangsu Province, there was a significant difference in R _eff (P < 0.05) between the CV-A16 and Total. In Hunan Province, the R _eff between CV-A16 and EV-A71&CV-A16, between CV-A16 and Total were significant (P < 0.05). In Chongqing Municipality, we found significant differences of the R _eff (P < 0.05) between CV-A16 and CV-A16&Others, and between Others and CV-A16&Others. In Jilin Province, significant differences of the R _eff (P < 0.05) were found between EV-A71 and Total, and between Others and Total.

Conclusion

The major pathogens of HFMD have changed annually, and the incidence of HFMD caused by others and CV-A16 has surpassed that of EV-A71 in recent years. Cross-regional differences were observed in the interactions between the pathogens.

Spatial-temporal-demographic and virological changes of hand, foot and mouth disease incidence after vaccination in a vulnerable region of China

Background

The enterovirus 71 (EV-A71) vaccine has been used in Hefei for several years, and the epidemiological significance of vaccination in this area is unclear. We aims to explore the spatial–temporal-demographic and virological changes of hand, foot and mouth disease (HFMD) after vaccination in China.

Methods

The data for HFMD from 2012 to 2020 were downloaded with the help of HFMD reporting system of Hefei Center for Disease Control and Prevention and combined with the EV-A71 vaccination status in Hefei. The study defined the period between 2012 to 2016 as the pre-vaccination period and explored the effect of vaccination on the incidence of HFMD by comparing the changes of HFMD before and after vaccination in terms of spatial, temporal, demographic and virological aspects.

Results

During the study period, a higher incidence occurred in urban area and the random distribution changed to a slight cluster after vaccination. HFMD incidence had inconsistent seasonality over years, with one or two incidence peaks in varying years. The morbidity decreased from 215.22/105 in 2012–2016 to 179.81/105 in 2017–2020 (p < 0.001). Boys, 0–4 years old children and Scattered children were more susceptible to HFMD compared with the others, the proportions decreased after vaccination except in Scattered children. The main pathogenic enterovirus gradually changed from EV-A71 to Other Enteroviruses, especially coxsackieviruses A6 (CV-A6) after the implementation of EV-A71 vaccination.

Conclusions

The EV-A71 vaccine was effective in reducing the incidence of HFMD and changing the spatial, temporal, demographic, and virological characteristic. These changes should be considered during the vaccination implementation to further reduce the disease burden of HFMD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-022-13860-z.