Foot-and-mouth disease (FMD) is an acute, severe, and highly contagious infectious disease caused by foot-and-mouth disease virus (FMDV), which seriously endangers the development of animal husbandry. The inactivated FMD vaccine is the main product for the prevention and control of FMD, which has been successfully applied to control the pandemic and outbreak of FMD. However, the inactivated FMD vaccine also has problems, such as the instability of antigen, the risk of spread of the virus due to incomplete inactivation during vaccine production, and the high cost of production. Compared with traditional microbial and animal bioreactors, production of antigens in plants through transgenic technology has some advantages including low cost, safety, convenience, and easy storage and transportation. Moreover, since antigens produced from plants can be directly used as edible vaccines, no complex processes of protein extraction and purification are required. But, there are some problems for the production of antigens in plants, which include low expression level and poor controllability. Thus, expressing the antigens of FMDV in plants may be an alternative mean for production of FMD vaccine, which has certain advantages but still need to be continuously optimized. Here we review the main strategies for expressing active proteins in plants, as well as the research progress on the expression of FMDV antigens in plants. We also discuss the current problems and challenges encountered, with the aim to facilitate related research.
Animals ; Foot-and-Mouth Disease Virus/genetics* ; Foot-and-Mouth Disease/prevention & control* ; Antigens, Viral/genetics* ; Viral Vaccines

Objective: To understand the vaccination status of enterovirus type 71 (EV71) inactivated vaccines in China from 2017 to 2021 and provide evidence for making policy on immunization strategy against hand, foot and mouth disease (HFMD). Methods: Using the reported dose number of EV71 vaccination and birth cohort population data collected by the China immunizaiton program information system to estimate the cumulative coverage of EV71 vaccine by the end of 2021 among the birth cohorts since 2012 at national, provincial, and prefecture levels, and analyze the correlation between the vaccination coverage and the potential influencing factors. Results: As of 2021, the estimated cumulative vaccination coverage of the EV71 vaccine was 24.96% in birth cohorts since 2012. The cumulative vaccination coverage was between 3.09% and 56.59% in different provinces, between 0 and 88.17% in different prefectures. There was a statistically significant correlation between vaccination coverage in different regions and the region's previous HFMD prevalence and disposable income per capita. Conclusions: Since 2017, the EV71 vaccines have been widely used nationwide, but the coverage of EV71 vaccination varies greatly among regions. Vaccination coverage is higher in relatively developed regions, and the intensity of previous epidemic of HFMD may have a certain impact on the acceptance of the vaccine and the pattern of immunization service. The impact of EV71 vaccination on the epidemic of HFMD requires further studies.
Humans ; Enterovirus A, Human ; Hand, Foot and Mouth Disease/prevention & control* ; Vaccines, Inactivated ; Viral Vaccines ; Enterovirus ; Vaccination ; China/epidemiology*

Humans ; Beijing ; Hand, Foot and Mouth Disease/epidemiology* ; China/epidemiology*

To further enhance the immune effect of the foot-and-mouth disease (FMD) virus-like particles (VLPs) vaccine, this study prepared FMDV VLPs-zeolitic imidazolate (framework-8, ZIF-8) complexes with different particle sizes. We used a biomimetic mineralization method with Zn²⁺ and 2-methylimidazole in different concentration ratios to investigate the effect of size on the immunization effect. The results showed that FMDV VLPs-ZIF-8 with three different sizes were successfully prepared, with an approximate size of 70 nm, 100 nm, and 1 000 nm, respectively. Cytotoxicity and animal toxicity tests showed that all three complexes exhibited excellent biological safety. Immunization tests in mice showed that all three complexes enhanced the titers of neutralizing and specific antibodies, and their immune effects improved as the size of the complexes decreased. This study showed that ZIF-8 encapsulation of FMDV VLPs significantly enhanced their immunogenic effect in a size-dependent manner.
Animals ; Mice ; Foot-and-Mouth Disease/prevention & control* ; Foot-and-Mouth Disease Virus ; Antibodies, Neutralizing ; Immunity, Humoral ; Immunization ; Vaccines, Virus-Like Particle ; Antibodies, Viral ; Viral Vaccines

Transient expression is the major method to express foot-and-mouth disease virus (FMDV) capsid proteins in mammalian cells. To achieve stable expression of FMDV capsid proteins and efficient assembly of virus like particles (VLPs) in cells, the plasmids of piggyBac (PB) transposon-constitutive expression and PB transposon-tetracycline (Tet) inducible expression vectors were constructed. The function of the plasmids was tested by fluorescent proteins. By adding antibiotics, the constitutive cell pools (C-WT, C-L127P) expressing P12A3C (WT/L127P) genes and the inducible cell pools (I-WT, I-L127P) expressing P12A3C (WT/L127P) genes were generated. The genes of green fluorescent protein, 3C protease and reverse tetracycline transactivator (rtTA) were integrated into chromosome, which was confirmed by fluorescence observation and PCR testing. The cell pool I-L127P has a stronger production capacity of capsid proteins and VLPs, which was confirmed by Western blotting and enzyme linked immunosorbent assay (ELISA), respectively. In conclusion, inducing the chromosomal expression of FMDV capsid proteins was firstly reported, which may facilitate the technical process of mammalian production of FMDV VLPs vaccine and the construction of mammalian inducible expression systems for other proteins.
Animals ; Foot-and-Mouth Disease Virus/genetics* ; Capsid Proteins ; Viral Proteins/metabolism* ; Foot-and-Mouth Disease/prevention & control* ; Tetracyclines/metabolism* ; Viral Vaccines ; Antibodies, Viral ; Mammals/metabolism*

Objective: To analyze the epidemiology and spatial-temporal distribution characteristics of hand, foot and mouth disease (HFMD) in Shanxi province. Methods: The data of HFMD in Shanxi province from 2009 to 2020 were collected from notifiable disease management information system of Chinese information system for disease control and prevention and analyzed by descriptive epidemiology, Joinpoint regression, spatial autocorrelation analysis and spatio- temporal scanning analysis. Results: A total of 293 477 HFMD cases were reported in Shanxi province from 2009 to 2020, with an average annual incidence of 67.64/100 000 (293 477/433 867 454), severe disease rate of 5.36/100 000 (2 326/433 867 454), severe disease ratio of 0.79%(2 326/293 477), mortality of 0.015/100 000 (66/433 867 454), and fatality rate of 22.49/100 000 (66/293 477). The reported incidence rate, severe disease rate, mortality rate and fatality rate of HFMD showed decreasing trends. The main high-risk groups were scattered children and kindergarten children aged 0-5. The incidence of HFMD had obvious seasonal variation, with two peaks every year: the main peak was during June-July, the secondary peak was during September-October and the peak period is from April to November. A total of 13 942 laboratory cases were confirmed, with a diagnosis rate of 4.75% (13 942/293 477), including 4 438 (35.11%, 4 438/293 477) Enterovirus A71 (EV-A71) positive cases, 4 609 (33.06%, 4 609/293 477) Coxsackievirus A16 (CV-A16) positive cases, and 4 895 (31.83%, 4 895/293 477) other enterovirus positive cases. There was a spatial positive correlation (Moran's I ranged from 0.12 to 0.58, all P<0.05) and the spatial clustering was obvious. High-risk regions were mainly distributed in Taiyuan in central Shanxi province, Linfen and Yuncheng in southern Shanxi province, and Changzhi in southeastern Shanxi province. Spatial-temporal scanning analysis revealed 1 the most likely cluster and 8 secondary likely clusters, of which the most likely cluster (RR=2.65, LLR=22 387.42, P<0.001) located in Taiyuan and Jinzhong city, Shanxi province, including 12 counties (districts), and accumulated from April 1, 2009 to November 30, 2018. Conclusions: There was obvious spatial-temporal clustering of HFMD in Shanxi province, and the epidemic situation was in decline. The key areas were the districts in urban areas and the counties adjacent to it. Meanwhile, the monitoring and classification of other enterovirus types of HFMD should be strengthened.
Child ; Humans ; Hand, Foot and Mouth Disease/epidemiology* ; Spatial Analysis ; Enterovirus Infections ; Spatio-Temporal Analysis ; Cluster Analysis

Objective: To analyze the spatiotemporal characteristics of hand,foot and mouth disease (HFMD) in China, explore the association of socioeconomic, population and health services factors with the incidence of HFMD in China, and provide information for the prevention and control of HFMD. Methods: Bayesian spatiotemporal model was used to fit the data of HFMD, evaluate the spatiotemporal variation of HFMD, and identify the potential association between the risk of HFMD and social, economic, population and health services. Results: From 2011 to 2018, a total of 17 118 050 HFMD cases, including 2 283 deaths, were reported in China. The reported incidence showed a fluctuating increase trend from 2011 to 2014, and a fluctuating decrease trend from 2014 to 2018. Meanwhile, there was a fluctuating decrease trend of mortality rate. The incidence of HFMD had spatial clustering, with the highest incidence in southern China with hot spot and high risk areas, and the lowest incidence in northwestern China where cold spot and low risk areas were found. The risk for HFMD was associated with GDP per capita (RR=3.54), number of industrial enterprises above designated size of 10 000 people (RR=1.61), urbanization rate (RR=3.00), birth rate (RR=2.36), number of beds in medical institutions per 10 000 people (RR=3.40), and green area in parks per capita (RR=0.57). Conclusions: The hotspot area for HFMD prevention and control in China was in the southeast coastal provinces from 2011 to 2018. In order to reduce the incidence of HFMD, it is necessary to increase the green area in parks per capita while accelerating urbanization process.
Humans ; Animals ; Bayes Theorem ; Foot-and-Mouth Disease ; China/epidemiology* ; Hand, Foot and Mouth Disease/epidemiology* ; Menthol

Objectives: Hand, foot and mouth disease (HFMD) is a widespread infectious disease that causes a significant disease burden on society. To achieve early intervention and to prevent outbreaks of disease, we propose a novel warning model that can accurately predict the incidence of HFMD. Methods: We propose a spatial-temporal graph convolutional network (STGCN) that combines spatial factors for surrounding cities with historical incidence over a certain time period to predict the future occurrence of HFMD in Guangdong and Shandong between 2011 and 2019. The 2011-2018 data served as the training and verification set, while data from 2019 served as the prediction set. Six important parameters were selected and verified in this model and the deviation was displayed by the root mean square error and the mean absolute error. Results: As the first application using a STGCN for disease forecasting, we succeeded in accurately predicting the incidence of HFMD over a 12-week period at the prefecture level, especially for cities of significant concern. Conclusions This model provides a novel approach for infectious disease prediction and may help health administrative departments implement effective control measures up to 3 months in advance, which may significantly reduce the morbidity associated with HFMD in the future.
China/epidemiology* ; Cities/epidemiology* ; Data Visualization ; Disease Outbreaks/statistics & numerical data* ; Forecasting/methods* ; Hand, Foot and Mouth Disease/prevention & control* ; Humans ; Incidence ; Neural Networks, Computer ; Reproducibility of Results ; Spatio-Temporal Analysis ; Time Factors

Animals ; Antibodies, Neutralizing ; Antibodies, Viral ; Foot-and-Mouth Disease Virus

China/epidemiology* ; Enterovirus ; Hand, Foot and Mouth Disease/epidemiology* ; Humans ; Infant ; Phylogeny ; Sequence Analysis, DNA