The stability and immunogenicity of formalin-inactivated Enterovirus A71 whole virion vaccine after ten years of low temperature storage.

BACKGROUND: Vaccine stability is an important issue for vaccine development, which affects whether the vaccine product is effective within a certain period of time in each progress. Hand, foot, and mouth diseases (HFMD) is an epidemic disease in young children usually caused by Enterovirus A group viruses, and the Enterovirus A71 (EV-A71) had caused several pandemics and public health issues around the world. After two decades of research and development, formalin-inactivated EV-A71 (FI-EV-A71) vaccines are the first to complete the phase III clinical trials for protection against EV-A71 infection. Currently, the shelf life of FI-EV-A71 vaccine product is set to be within 18 months, but the stability and the effectiveness of the FI-EV-A71 whole virion when stored long-term at low temperature remains undetermined. METHODS: Assessing the long-term storage properties of viral particles facilitates flexibility in manufacturing of vaccine products. In this study, the stability profiles of FI-EV-A71 vaccine lots and bulks after long-term of low temperature storage were analyzed by protein tests, particle measurement and animal immunization study. RESULTS: After over ten years of storage, the reduction of protein concentration in the FI-EV-A71 bulk samples is less than 30 % and the antigenic content remained in a suspended, particulate state. Both the packed FI-EV-A71 final vaccine products and the FI-EV-A71 antigens adjuvant premix bulk could elicit strong neutralizing responses in mice. CONCLUSION: After ten years of low temperature storage, the FI-EV-A71 vaccine still presents decent stability and good immunogenicity.

Propagation and immunological characterization of coxsackievirus A10 in a serum-free HEK293A cell culture system.

Coxsackievirus A10 (CVA10) is one of enteroviral pathogens that cause the hand, foot, and mouth disease (HFMD). Since CVA10 was reported to be not easily propagated in the Vero cell culture, a feasible manufacture process for producing formalin-inactivated CVA10 vaccine is urgently needed. Several cell lines that commonly used for viral vaccine production was tested for CVA10 (M2014 strain) culture in this study, and our result showed that CVA10 could be easily propagated in the HEK293A cells. A serum-free HEK293A cell culture system was developed for CVA10 production and the yields have reached over 108 TCID50/mL. The biochemical and immunogenic properties of CVA10 particles obtained from this serum-free HEK293A culture were identical to our previous study. Two major particles of CVA10 were separated by ultracentrifugation, and only the infectious mature particles were capable of inducing CVA10 neutralizing antibody responses in the mouse immunogenicity studies. Additionally, we found that coxsackievirus A6 and enterovirus A71 could also be easily propagated using this serum-free HEK293A cell culture system. Our results provide a solution to overcome the obstacle in the propagation of CVA10 and facilitate the development of multivalent vaccines for prevention of HFMD.

Global Trends in Green Space and Senior Mental Health Studies: Bibliometric Review.

The Sustainable Development Goals and the World Health Organization have prioritized senior mental health as an important goal. Senior mental health is a critical issue within the global public health sphere. Notably, green spaces are a useful alternative for improving senior mental health. Many studies have focused on green space and senior mental health, especially on their connection and relationship. However, this research topic lacks a comprehensive and systematic review. Owing to the lack of critical reviews, this study clarified the trend, progress, status, and focus of studies on green spaces and senior mental health using bibliometric analysis of literature within the Web of Science database. The literature analysis within this study specifically focused on the following, including the country/region contribution analysis, institution contribution analysis, keyword analysis, and highly productive journal analysis. Furthermore, this study systematically recorded the content of green space and senior mental health, identified the gap that exists, and provided future frontier directions or issues for research. These contribute toward comprehending the progress and content of this research topic and further provide a guide, reference, and inspiration for possible future research.

Separation and purification of highly infectious enterovirus A71 particles using a strong anion-exchange column.

Virions produced from cell culture is the primary source for production of formalin-inactivated whole virus vaccines for enteroviruses. EV-A71 particles produced from culture system comprise two major types, the immature/empty (E)-particle and the mature/full (F)-particle, which both exhibit low isoelectric point (pI) values but have distinct differences in infectivity and immunogenicity. Although EV-A71 particles can conventionally be separated into E-particle and F-particle using sucrose gradient ultracentrifugation, this procedure is cumbersome and difficult to put into practice for vaccine production. Methods based on ion-exchange chromatography have been exploited to improve the purification efficacy; however, none of them are capable of separating the E- and F-particles efficiently. In this study, we aimed to develop an approach to isolate and purify the highly immunogenic mature EV-A71 particles. By applying a step gradient elution procedure, we successfully isolated the viral structure protein VP0-cleaved particles of EV-A71 from a mixture of cultured viral solution using the Q-membrane anion-exchange chromatography. The elution started with 0.1x phosphate buffered saline (PBS) solution while increasing the percentage of 1x PBS containing 1M NaCl in sequential steps. By this procedure, the VP0-cleaved mature particles and VP0-uncleaved immature particles of EV-A71 could be separated into different fractions in Q-membrane with gradually increased NaCl concentration in elution buffer. The purified VP0-cleaved particles were shown to have characteristics equivalent to those of the highly infectious F-particles of EV-A71. The overall recovery rate for the mature EV-A71 particles by Q-membrane is 56% and its purity was shown to be equivalent to those isolated by the sucrose gradient ultracentrifugation. Our approach provides a simple and efficient purification method for recovering mature, highly infectious virus particles from the EV-A71 culture bulk.

Multiple pathways and mediation effects of built environment on kidney disease rate via mitigation of atmospheric threats.

Air pollution and high temperatures can increase kidney disease rate, especially under climate change. A well-designed urban environment has mediating effects on atmospheric environmental threats and promoting human health, but previous studies have overlooked these effects. This study used partial least squares modeling and urban-scale data from Taiwan to identify the crucial effects (i.e., direct, indirect, and total effects) and pathways of urban form (i.e., urban development intensity, land-use mix, and urban sprawl), urban greening (i.e., green coverage), urban industrial status (e.g., industrial level), atmospheric environment (i.e., high temperature and air pollution), and socioeconomic status (i.e., elderly ratio, medical resources, and economic status) on kidney disease rate. Maximizing land-use mix and green coverage and minimizing urban development intensity, urban sprawl, and industrial levels could help reduce kidney disease rate. Air pollution and high temperature had a mediation effect of built environment on kidney disease rate; with the mediation effect of air pollution was greater than that of high temperature. Furthermore, air pollution, high temperature, and elderly ratio increased kidney disease rate, whereas medical resources decreased kidney disease rate. This study is the first to consider the impact (i.e., direct, indirect, and total effects) and pathways of built environment characteristics on kidney disease rate. The findings revealed that an appropriate urban policy might be a practical strategy and lower kidney disease rate for a healthy city development. Moreover, this study provides a new approach for clarifying complex relationships and identifying crucial factors.

Exploring multiple pathways and mediation effects of urban environmental factors for suicide prevention.

Public health is threatened by air pollution and high temperature, especially in urban areas and areas impacted by climate change. Well-designed urban forms have co-benefits on promoting human health and mediating atmospheric environment-related threats (e.g., high temperature and air pollution). Previous studies overlooked these mediating effects of urban form on suicide mortality. This study used partial least squares modeling and countywide data in Taiwan to identify the crucial influences and pathways of urban environment, socioeconomic status, and diseases on suicide mortality. The model considered the impact of the characteristics of urban form (i.e., urban development intensity, land mix, and urban sprawl), urban industrial status (i.e., industrial level), urban greening (i.e., green coverage), disease (i.e., important diseases morbidity of human immunodeficiency virus [HIV], cerebrovascular disease [CVD], chronic liver disease and cirrhosis [CLDC], nephritis, nephrotic syndrome and nephrosis [NNSN], malignant tumor [MT]), socioeconomic status (i.e., income level and aging population rate), and the atmospheric environment (i.e., air pollution and high temperature) on suicide mortality. Optimizing land mix and minimizing urban development intensity and urban sprawl have been found to reduce suicide mortality. The mediating effect of urban form on suicide mortality originated from air pollution and high temperature, and mediating air pollution was greater than high temperature. Furthermore, industrial level, important diseases (HIV, CVD, CLDC, NNSN, and MT) morbidity, an aging population rate, air pollution, and high temperature were associated with an increase in suicide mortality, whereas green coverage and income level were associated with a reduction in suicide rates. The findings demonstrate that appropriate urban policy and urban planning may lower suicide mortality, be useful strategies for suicide prevention, and be a foundation for building a healthy city. Moreover, this study provides clarity on the complex relationship of suicide and the urban environment while identifying crucial factors.

Crucial factors of the built environment for mitigating carbon emissions.

Global warming and environmental changes are becoming increasingly threatened by carbon emissions, especially in urban areas. Low-carbon cities have the co-benefits of mediating environmental threats and lowering carbon emissions. However, the direct and indirect pathways and effects between the built environment and carbon emissions remain unclear, limiting low-carbon city development. Therefore, this study used partial least squares (PLS) modeling and urban-scale data from nineteen counties in Taiwan to identify the crucial effects and pathways affecting carbon emissions. The model considered the impacts of the characteristics of urban form (i.e., density, land mix, city size, urban sprawl, and jobs-housing balance), urban function (i.e., industrial and commercial levels), urban transportation, and urban greening on carbon emissions. The results reveal that minimizing city size, urban sprawl, industrial level, and transportation status, and maximizing density, land mix, commercial levels, and urban green coverage could reduce carbon emissions. This is the first study to apply PLS modeling to identify variable pathways and evaluate both direct and indirect effects of built environment characteristics on carbon emissions. Findings demonstrated that appropriate urban policies and planning, such as compact cities, green cities, or transit-oriented development, might lower carbon emissions and thus further serve as useful strategies for building low-carbon cities.

A community-based study on associations between PM2.5 and PM1 exposure and heart rate variability using wearable low-cost sensing devices.

Few studies have investigated the effect of personal PM2.5 and PM1 exposures on heart rate variability (HRV) for a community-based population, especially in Asia. This study evaluates the effects of personal PM2.5 and PM1 exposure on HRV during two seasons for 35 healthy adults living in an urban community in Taiwan. The low-cost sensing (LCS) devices were used to monitor the PM levels and HRV, respectively, for two consecutive days. The mean PM2.5 and PM1 concentrations were 13.7 ± 11.4 and 12.7 ± 10.5 µg/m3 (mean ± standard deviation), respectively. Incense burning was the source that contributed most to the PM2.5 and PM1 concentrations, around 9.2 µg/m3, while environmental tobacco smoke exposure had the greatest impacts on HRV indices, being associated with the highest decrease of 20.2% for high-frequency power (HF). The results indicate that an increase in PM2.5 concentrations of one interquartile range (8.7 µg/m3) was associated with a change of -1.92% in HF and 1.60% in ratio of LF to HF power (LF/HF). Impacts on HRV for PM1 were similar to those for PM2.5. An increase in PM1 concentrations of one interquartile range (8.7 µg/m3) was associated with a change of -0.645% in SDNN, -1.82% in HF and 1.54% in LF/HF. Stronger immediate and lag effects of PM2.5 exposure on HRV were observed in overweight/obese subjects (body mass index (BMI) ≥24 kg/m2) compared to the normal-weight group (BMI <24 kg/m2). These results indicate that even low-level PM concentrations can still cause changes in HRV, especially for the overweight/obese population.

Multiple impacts and pathways of urban form and environmental factors on cardiovascular mortality.

Air pollution and heat are significant threats to public health, especially in urban areas with intensive human activities under the trend of climate change. However, the mediation effects of urban form on health via air pollution and heat have been overlooked in previous investigations. This study explored the potential impacts and pathways of urban form on cardiovascular mortality through air pollutants and heat by using partial least squares model with data from Taiwan. The measurable characteristics of urban form include city size, urban sprawl, and mixed land use. Other factors that influence cardiovascular mortality, such as urban industrial level, economic status, aging population, and medical resource, were also considered in the model. Results revealed that maximizing mixed land use and minimizing city size and urban sprawl can help reduce cardiovascular mortality, and the minimizing city size was the most important one. Urban industrial level, economic status, aging population, and medical resource were also influential factors. This is the first study to consider the pathways and impacts of urban form on cardiovascular mortality, and our results indicate that proper urban planning and policy could reduce cardiovascular mortality.

Mediation pathways and effects of green structures on respiratory mortality via reducing air pollution.

Previous studies have shown both health and environmental benefits of green spaces, especially in moderating temperature and reducing air pollution. However, the characteristics of green structures have been overlooked in previous investigations. In addition, the mediation effects of green structures on respiratory mortality have not been assessed. This study explores the potential mediation pathways and effects of green structure characteristics on respiratory mortality through temperature, primary and secondary air pollutants separately using partial least squares model with data from Taiwan. The measurable characteristics of green structure include the largest patch percentage, landscape proportion, aggregation, patch distance, and fragmentation. The results showed that mortality of pneumonia and chronic lower respiratory diseases could be reduced by minimizing fragmentation and increasing the largest patch percentage of green structure, and the mediation effects are mostly through reducing air pollutants rather than temperature. Moreover, a high proportion of but fragmented green spaces would increase secondary air pollutants and enhance health risks; demonstrating the deficiency of traditional greening policy with primary focus on coverage ratio. This is the first research focusing on mediation effects of green structure characteristics on respiratory mortality, revealing that appropriate green structure planning can be a useful complementary strategy in environmental health management.

Can green structure reduce the mortality of cardiovascular diseases?

Previous studies have shown that green spaces are beneficial to health; however, few studies have analyzed the relationship between green structure and mortality of cardiovascular disease. Green structure may mediate the effects of air pollution and temperature on health. This work applies partial least squares (PLS) modeling to analyze the degree to which green structure reduces mortality of cardiovascular disease, using Taipei Metropolitan Area as an empirical case. In addition to clarifying the complex relationships and effects of green structure, air pollution, temperature, and mortality of cardiovascular disease, this study demonstrates that green structure has a significant influence on mortality of cardiovascular disease because it reduces the effects of air pollution and heat. The most crucial elements for planning a healthy living environment are the maximization of the largest green patch proportion and the minimization of green space fragmentation. Moreover, to enhance the benefits of greening city spaces on health, this work proposes several strategies for connecting fragmentary green spaces, expanding green patches to the largest possible proportion, and managing green spaces. The proposed strategies may serve as a reference for other metropolitan areas with features similar to those of the study area.