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

IntroductionVaccine hesitancy may increase infectious disease burden and impede disease control efforts, while few studies have measured such a phenomenon with a standardized tool in China. This study aimed to test the validation of the Vaccine Hesitancy Scale (VHS) developed by the WHO SAGE Working Group among caregivers and examine demographic characteristics associated with caregiver hesitancy in six provinces of China.MethodsUsing a multistage sampling design, this study was conducted in 36 immunization clinics in six provinces from December 2019 to August 2020. Caregivers of children aged 0–3  years were included. The VHS was used to assess vaccine hesitancy. The construct validity and internal consistency of the scale were assessed. Associations between caregivers’ characteristics and vaccine hesitancy were examined by simple and multiple linear regression models.ResultsOf the 3,359 participants included, a two-factor structure within the scale was identified, consisting of “lack of confidence” (1.89 ± 0.53) and “risks” (3.20 ± 0.75). Caregivers engaged in medical work expressed more confidence and were less concerned about risks compared to those of non-medical staff (p < 0.05). Participants with higher income levels were more confident (p < 0.05), while those surveyed after the COVID-19 pandemic, who were mothers, who had an older child, or who were raising a second or above birth child, had less concern about risks (p < 0.05).DiscussionWe found that the VHS had acceptable reliability and construct validity and caregivers’ hesitancy was driven more by concerns about risks than by the lack of confidence. Countering these concerns will be particularly important among non-medical staff, lower income, child’s fathers, having a younger child, or raising first-birth child groups

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

Cost-effectiveness of the Haemophilus influenzae type b vaccine for infants in mainland China

Objective: The aims of this study were to estimate the cost-effectiveness of the Haemophilus influenzae type b (Hib) vaccine for the prevention of childhood pneumonia, meningitis and other vaccine-preventable diseases in mainland China from a societal perspective and to provide information about the addition of the Hib vaccine to Chinese immunization programs. Methods: A decision tree and the Markov model were used to estimate the costs and effectiveness of the Hib vaccine versus no Hib vaccine for a birth cohort of 100,000 children in 2016. The disease burden was estimated from the literature, statistical yearbooks and field surveys. Vaccine costs were calculated from government reports and the United Nations International Children's Emergency Fund (UNICEF) website. The WHO cost-effectiveness thresholds were used to evaluate the Hib vaccine intervention. A one-way sensitivity analysis and probabilistic sensitivity analysis were performed to evaluate the parameter uncertainties. Results: Within the hypothetical cohort, under a vaccination coverage of 90%, the Hib vaccine could reduce 91.4% of Hib pneumonia and 88.3% of Hib meningitis; the Hib vaccine could also prevent 25 deaths, 24 meningitis sequelae cases and 9 hearing loss cases caused by Hib infection. From a societal perspective, the incremental cost-effectiveness ratio (ICER) of the Hib vaccine compared with no vaccination was US$13,640.1 at the market price, which was less than 3 times the GDP per capita of China in 2016. The ICER of the Hib vaccine was US$ −59,122.9 at the UNICEF price, indicating a cost savings. The largest portion of the uncertainty in the result was caused by the annual incidence of all-cause pneumonia, proportion of pneumonia caused by Hi, vaccine costs per dose, annual incidence of Hib meningitis and costs per episode of meningitis. The models were robust considering parameter uncertainties. Conclusion: The Hib vaccine is a cost-effective intervention among children in mainland China. The cost of Hib vaccine should be reduced, and it should be introduced into Chinese immunization programs

Vaccine Coverage and Effectiveness in a School-Based Varicella Outbreak in Jinan Prefecture, Shandong Province

Background: Licheng District of Jinan Prefecture reported a school-based varicella outbreak. We conducted an investigation to analyze the epidemiology and scope of the outbreak, determine varicella vaccine coverage on the school campus, and estimate varicella vaccine effectiveness (VE). Methods: In the epidemiological investigation, we determined the attack rate, the clinical manifestations of varicella cases, and histories of prior varicella disease and varicella vaccination. We tested students for presence of serum IgM antibodies, and we attempted to isolate the varicella virus from vesicular fluid samples. We used chi-square to compare incidences between classes and floors. VE was estimated using a retrospective cohort study. Results: There were 13 varicella cases in the outbreak. All were among fourth grade students - twelve in Class 7 and one in Class 6. The attack rate in the two classrooms was 14.3% (13/91). Clinical symptoms were rash (100%) and fever (46.15%). All cases were reported within one average incubation period, and the epidemic curve suggested common exposure. Six of the 13 cases previously received one dose of varicella vaccine with a median time between vaccination and infection of 9 years; the other seven cases had not been vaccinated. Varicella vaccine coverage with one or more doses was 81.31%; 2-dose coverage was 38.15%. The median age of receipt of dose 1 was 1.18 years, and median age for receiving dose 2 was 5.12 years. One-dose varicella VE was 73.2% (95% confidence interval: 37.0%, 88.6%), and two-dose VE was 100%. Conclusions: Varicella vaccine coverage has been gradually increasing in recent years, as ≥1-dose and 2-dose coverage rates are higher in younger children than older children. High one-dose vaccination coverage limited the outbreak scope and led to the breakthrough cases being mild. Mild cases were difficult to detect in a timely manner. Varicella vaccine was highly effective, with 1-dose VE of 73% nine years after vaccination and 2-dose VE of 100%. We strongly recommended that all school students receive two doses of varicella vaccine

The etiology of community-acquired pneumonia among children under 5 years of age in mainland China, 2001–2015: A systematic review

Background: The aim of this systematic review was to examine the etiology of community-acquired pneumonia (CAP) among Chinese children younger than 5 y and provide evidence for further cost-effectiveness analyses for vaccine development, diagnostic strategies and empirical treatments. Methods: The literature review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Data were obtained by searching PubMed, Embase, Web-of Science, and the Chinese databases Wanfang Data and China National Knowledge Infrastructure. All CAP etiological studies on children under 5 y of age from China published in Chinese and English between the years of 2001 and 2015 were included. A total of 48 studies were included in the final review, comprising 100 151 hospitalized children with CAP episodes. Heterogeneity and the percentage of variation between studies was analyzed based on Q statistic and I2 indices, respectively. Random effect models were used to calculate the weighted average rate in all analyses. Results: The most frequently detected bacterial agents were Klebsiella pneumoniae (5.4%), Streptococcus pneumoniae (5.2%), Escherichia coli (5.2%), Staphylococcus aureus (3.9%), Haemophilus influenza (3.6%) and Haemophilus parainfluenzae (3.3%). The most frequently detected viruses were human rhinovirus (20.3%, in just 2 studies), respiratory syncytial virus (RSV, 17.3%), human bocavirus (9.9%), parainfluenza virus (5.8%), human metapneumovirus (3.9%) and influenza (3.5%). Mycoplasma pneumoniae and Chlamydophila pneumoniae were identified in 9.5% and 2.9%, respectively, of children under 5 y of age with CAP. Conclusion: This article provides the most comprehensive analysis to date of the factors contributing to CAP in children under 5 y of age. S. pneumoniae, H. influenzae and influenza were the most common vaccine-preventable diseases in children. Corresponding, vaccines should be introduced into Chinese immunization programs, and further economic evaluations should be conducted. RSV is common in Chinese children and preventative measures could have a substantial impact on public health. These data also have major implications for diagnostic strategies and empirical treatments

Protective Effects of Fucoidan on Aβ25–35 and d-Gal-Induced Neurotoxicity in PC12 Cells and d-Gal-Induced Cognitive Dysfunction in Mice

Alzheimer’s disease (AD) is a chronic neurodegenerative disease which contributes to memory loss and cognitive decline in the elderly. Fucoidan, extracted from brown algae, is a complex sulfated polysaccharide and potential bioactive compound. In this study, we investigated whether fucoidan protects PC12 cells from apoptosis induced by a combination of beta-amyloid 25–35 (Aβ25–35) and d-galactose (d-Gal), and improves learning and memory impairment in AD model mice. The results indicated that fucoidan could inhibit the release of cytochrome c from the mitochondria to cytosol and activation of caspases, and increase the expression of apoptosis inhibitor proteins (IAPs), including livin and X-linked IAP (XIAP) in PC12 cells damaged by Aβ25–35 and d-Gal-induction. Fucoidan reversed the decreased activity of acetylcholine (ACh) and choline acetyl transferase (ChAT), as well as the increased activity of acetylcholine esterase (AChE), in AD model mice induced by infusion of d-Gal. Furthermore, fucoidan improved antioxidant activity in vitro and in vivo by activation of superoxide dismutase (SOD) and glutathione (GSH). These results suggested that fucoidan could protect PC12 cells from apoptosis and ameliorate the learning and memory impairment in AD model mice, which appeared to be due to regulating the cholinergic system, reducing oxidative stress, and inhibiting the caspase-dependent apoptosis pathway

Prioritization of Vaccines for Inclusion into China’s Expanded Program on Immunization: Evidence from Experts’ Knowledge and Opinions

Background: Vaccine developers in China have made an increasing number of infectious diseases preventable through vaccination. An appropriate decision-making procedure is necessary for making wise decisions on whether to introduce new vaccines into the Expanded Program on Immunization (EPI). When there are several vaccines that could potentially be considered, a scientifically justifiable mechanism is needed for prioritizing and sequencing vaccines for consideration. Methods: We used a modified Delphi technique (MDT) to develop and refine an indicator system to prioritize vaccines and make policy recommendations concerning their introduction into China’s EPI system. From January through May 2021, thirty-nine experts were recruited and participated in a two-round Delphi survey that was based on a set of candidate indicators obtained through a literature review and reference to the WHO vaccine introduction recommendations. Using the resulting indicator system, we conducted a third consultation with a multi-disciplinary group of experts who scored five program-eligible candidate vaccines to determine prioritization and sequencing for consideration of inclusion into the EPI. Results: Response rates of the thirty-nine experts were 100% and 97.4% across the two rounds. Authority coefficients from rounds one to three were over 0.70, reflecting the high accuracy and reliability of the consultation. Coordination coefficients of importance scores for primary, secondary, and tertiary indicators were 0.486, 0.356, 0.275 in round one, and 0.405, 0.340, and 0.236 in round two. According to the scores from 30 experts using our indicator system, the sequence and scores (1–10 scale, 10 highest) of 5 candidate vaccines were varicella (6.91), meningococcal conjugate AC (6.83), Hib (6.74), influenza (6.56), and EV71 (6.17) vaccines. Conclusions: A modified Delphi technique effectively built a scientific, rational, comprehensive, and systematic indicator system for prioritizing vaccine candidates for consideration of inclusion into the EPI. The rank order will be used by the technical working groups of China’s National Immunization Advisory Committee to sequentially develop and present Evidence-to-Recommendation tables for making policy recommendations

Impact of the Ebola outbreak on routine immunization in western area, Sierra Leone - a field survey from an Ebola epidemic area

Abstract Background Since March 2014, the Ebola Virus Disease (EVD) outbreak in West Africa disrupted health care systems - especially in Guinea, Liberia and Sierra Leone – with a consequential stress on the area’s routine immunization programs. To address perceived decreased vaccination coverage, Sierra Leone conducted a catch-up vaccination campaign during 24–27 April 2015. We conducted a vaccination coverage survey and report coverage estimates surrounding the time of the EVD outbreak and the catch-up campaign. Methods We selected 3 villages from each of 3 communities and obtained dates of birth and dates of vaccination with measles vaccine (MV) and the 3rd dose of Pentavalent vaccine (Pentavalent3) of all children under 4 years of age in the 9 selected villages. Vaccination data were obtained from parent-held health cards. We calculated the children’s MV and Pentavalent3 coverage rates at 3 time points, 1 August 2014, 1 April 2015, and 1 May 2015, representing coverage rates before the EVD outbreak, during the EVD outbreak, and after the Maternal and Child Health Week (MCHW) catch-up campaign. Results The final sample size was 168 children. MV coverage among age-eligible children was 71.3% (95% confidence interval [CI]: 62.1% - 80.4%) and 45.7% (95% CI: 29.2% - 62.2%) before and during the outbreak of EVD, respectively, and was 56.8% (95% CI: 40.8% - 72.7%) after the campaign. Pentavalent3 coverage among age-eligible children was 79.8% (95% CI: 72.6% - 87.0%) and 40.0% (95% CI: 22.5% - 57.5%) before and during the outbreak of EVD, and was 56.4% (95% CI: 39.1% - 73.4%) after the campaign. Conclusions Coverage levels of MV and Pentavalent3 were low before the EVD outbreak and decreased further during the outbreak. Although the MCHW catch-up campaign increased coverage levels, coverage remained below pre-outbreak levels. High-quality supplementary immunization activities should be conducted and routine immunization should be strengthened to address gaps in immunity among children in this EVD-affected area