African swine fever(ASF)caused by African swine fever virus(ASFV)is a febrile,hem-orrhage and highly fatal infectious disease in pigs,which poses a serious threat to the global pig in-dustry.Currently,no vaccine is available for the prevention and control of ASF,and several ASF vaccines,including gene deletion attenuated live vaccines,live vector vaccines,and subunit vaccines are under the development stage in the laboratory research.As one of the most promising vaccines,live vector vaccine has the characteristic of safety and simulation of the pathogen natural infection to effectively stimulate the innate and adaptive immune responses,which becomes one of the hotspots in the research and development of novel ASF vaccines.This review focuses on the pro-gress in using modified viruses as vectors for ASF live vector vaccines,and aims to provide valua-ble information for future development of safe and effective ASF vector vaccines.

African swine fever(ASF)is an acute,febrile,and highly fatal disease caused by African swine fever virus(ASFV)in pigs.Given the current lack of commercial vaccines and the continu-ous evolution of ASFV in recent years,the emergence of moderately virulent genotype Ⅱ strains and the introduction of genotype Ⅰ attenuated strains have led to persistent and chronic infections in pigs.Therefore,the detection of specific antibodies against ASFV has become imperative.In this study,we established a competitive chemiluminescence immunoassay(p30-cCLIA)for detecting ASFV p30 antibodies using p30 monoclonal antibodies.By detecting sera with clear negative and positive backgrounds,we determined that the Cut-off value of this method was 50％,with both di-agnostic sensitivity(Dsn)and diagnostic specificity(Dsp)reaching 100％.Under optimal reaction conditions,we screened out an enzyme-labeled stabilizer suitable for p30 monoclonal antibody 16-5E7E8-HRP.Furthermore,the sensitivity of the established p30-cCLIA method was higher than that of the commercial blocking ELISA kit(1∶2 048 vs 1∶512)and exhibited good repeatability.Detection of sera positive for other porcine virus infections showed no cross-reactivity.The estab-lishment of this method provides a powerful tool for early diagnosis of ASF.

Although no cross protection was observed between different serotypes of foot-and-mouth disease virus(FMDV),there were cross-reactivity between different serotypes of antibodies produced after vaccination,the aim of this paper was to prepare the neutralizing monoclonal anti-body against Foot-and-mouth disease virus(FMDV)serotype O,and to develop the method to dis-tinguish antibody against FMDV serotype O and A based on mAb.The inactivated FMDV serotype O was used as antigen in mAb production,a series of GST fusion overlapping peptides and trun-cated peptides expressed in Escherichia coli were used to identify antigenic epitope recognized by monoclonal antibodies.In order to verify feasibility of the screened monoclonal antibodies in diag-nosis,20 positive serum of FMDV serotype O and A,20 negative serum with known background were detected by blocking ELISA.Results were as follows:five monoclonal antibodies were suc-cessfully screened.The five monoclonal antibodies showed good reactivity with FMDV serotype O,but did not react with FMDV serotype A by Western blot and IFA,these mAbs showed neutrali-zing ability to FMDV/O/MY98/GZBY/2013 by VNT.The same epitope was identified by five monoclonal antibodies,the minimum epitope was145 RGDLQVLA152,Arg145 and Gln149 were key a-mino acids of the epitope.Sequence alignment analysis revealed that the identified epitopes were conserved among most of O type FMDV strains,but Gln149 was mutated among all A,Asia 1 and SAT1-3 type FMDV strains.The mAb-8C5D3 distinguished between antibody of FMDV serotype O and FMDV serotype A by blocking ELISA.The results provided materials for development of O type FMDV antibody detection kit and evaluation of vaccine immune effect.

Although no cross protection was observed between different serotypes of foot-and-mouth disease virus(FMDV),there were cross-reactivity between different serotypes of antibodies produced after vaccination,the aim of this paper was to prepare the neutralizing monoclonal anti-body against Foot-and-mouth disease virus(FMDV)serotype O,and to develop the method to dis-tinguish antibody against FMDV serotype O and A based on mAb.The inactivated FMDV serotype O was used as antigen in mAb production,a series of GST fusion overlapping peptides and trun-cated peptides expressed in Escherichia coli were used to identify antigenic epitope recognized by monoclonal antibodies.In order to verify feasibility of the screened monoclonal antibodies in diag-nosis,20 positive serum of FMDV serotype O and A,20 negative serum with known background were detected by blocking ELISA.Results were as follows:five monoclonal antibodies were suc-cessfully screened.The five monoclonal antibodies showed good reactivity with FMDV serotype O,but did not react with FMDV serotype A by Western blot and IFA,these mAbs showed neutrali-zing ability to FMDV/O/MY98/GZBY/2013 by VNT.The same epitope was identified by five monoclonal antibodies,the minimum epitope was145 RGDLQVLA152,Arg145 and Gln149 were key a-mino acids of the epitope.Sequence alignment analysis revealed that the identified epitopes were conserved among most of O type FMDV strains,but Gln149 was mutated among all A,Asia 1 and SAT1-3 type FMDV strains.The mAb-8C5D3 distinguished between antibody of FMDV serotype O and FMDV serotype A by blocking ELISA.The results provided materials for development of O type FMDV antibody detection kit and evaluation of vaccine immune effect.

African swine fever(ASF)caused by African swine fever virus(ASFV)is a febrile,hem-orrhage and highly fatal infectious disease in pigs,which poses a serious threat to the global pig in-dustry.Currently,no vaccine is available for the prevention and control of ASF,and several ASF vaccines,including gene deletion attenuated live vaccines,live vector vaccines,and subunit vaccines are under the development stage in the laboratory research.As one of the most promising vaccines,live vector vaccine has the characteristic of safety and simulation of the pathogen natural infection to effectively stimulate the innate and adaptive immune responses,which becomes one of the hotspots in the research and development of novel ASF vaccines.This review focuses on the pro-gress in using modified viruses as vectors for ASF live vector vaccines,and aims to provide valua-ble information for future development of safe and effective ASF vector vaccines.

African swine fever(ASF)is an acute,febrile,and highly fatal disease caused by African swine fever virus(ASFV)in pigs.Given the current lack of commercial vaccines and the continu-ous evolution of ASFV in recent years,the emergence of moderately virulent genotype Ⅱ strains and the introduction of genotype Ⅰ attenuated strains have led to persistent and chronic infections in pigs.Therefore,the detection of specific antibodies against ASFV has become imperative.In this study,we established a competitive chemiluminescence immunoassay(p30-cCLIA)for detecting ASFV p30 antibodies using p30 monoclonal antibodies.By detecting sera with clear negative and positive backgrounds,we determined that the Cut-off value of this method was 50％,with both di-agnostic sensitivity(Dsn)and diagnostic specificity(Dsp)reaching 100％.Under optimal reaction conditions,we screened out an enzyme-labeled stabilizer suitable for p30 monoclonal antibody 16-5E7E8-HRP.Furthermore,the sensitivity of the established p30-cCLIA method was higher than that of the commercial blocking ELISA kit(1∶2 048 vs 1∶512)and exhibited good repeatability.Detection of sera positive for other porcine virus infections showed no cross-reactivity.The estab-lishment of this method provides a powerful tool for early diagnosis of ASF.

Background In recent years, regional high-temperature weather in summer occurs frequently in China. Heat stroke is the most representative meteorological disease caused by high temperature. In order to improve monitoring, early warning, prevention, and control of heat stroke, it is of great significance to understand the epidemiological characteristics of heat stroke and the associated impact of heatwave. Objective To understand the epidemiological characteristics of heat stroke cases in Jinan City, and to explore the effects of heatwave exposure on heat stroke. Methods Case reports of heat stroke and daily data of meteorological factors in Jinan City from 2017 to 2022 were collected. We described the temporal, population, and regional distribution characteristics of heat stroke cases in Jinan City, and used a time-stratified case-crossover design combined with conditional logistic regression model to explore the effects of heatwave exposure on heat stroke under 12 heatwave definitions (different combinations of intensity and duration). The cut-off percentiles used for heatwave definitions were the 90th (P₉₀), 95th (P₉₅), 97.5th (P_97.5), and 99th (P₉₉) percentiles of daily mean temperature; the durations were ≥ 2 d, ≥ 3 d, and ≥ 4 d, respectively. P_i(k), where i is temperature threshold, and k is duration. For example, the definition of a heatwave was notated as P₉₀(2), indicating that the daily mean temperature is ≥ P₉₀ and lasts for ≥ 2 d. Alternatively, lag01 denotes the cumulative lag effect with a 1 d lag, and so on. Results A total of 1394 cases of heat stroke were reported in Jinan City from 2017 to 2022, including 581 mild cases and 813 severe cases, and 85 deaths were reported, with a cumulative fatality rate of 6.10%. The cases of heat stroke reported each year during the study period were concentrated from June to August and peaked in July (665 cases, 47.70%). The sex ratio of males to females in heat stroke cases was 2.02:1. A high incidence of heat stroke was in 50-89 years, with a smaller peak occurring in the age group of 50-59 years and a larger peak in the age group of 70-79 years, respectively. The high-incidence areas of heat stroke were distributed in the western part of Jinan City where city centers situated (Tianqiao District, 274 cases, 19.66%; Huaiyin District, 223 cases, 16.00%) and in the surrounding rural areas (Pingyin County, 254 cases, 18.22%). The effect of heatwave exposure on heat stroke was statistically significant during the study period. The largest effect estimates for the effect on heat stroke occurred under the heatwave definitions of P₉₉(2), P_97.5(3), and P_97.5(4) at lag04, lag03, and lag04, where corresponding OR (95%CI) values were 9.27 (4.71, 14.24), 8.95 (6.17, 12.98), and 8.22 (4.91, 13.78), respectively. The exposure-response curve showed that the risk of heat stroke tended to increase with the increase of average daily temperature. Conclusion July is the key period for the occurrence of heat stroke among Jinan City residents, while male cases are predominant, more serious cases, age concentration in the 50-89 years. The occurrence of heatwave can further increase the risk of heat stroke with a significant lag effect.

Objective:To study the levels and variation of equilibrium factor in indoor environment.Methods:A one-year continuous measurement of radon concentration and equilibrium equivalent radon concentration was carried out in an indoor office building of Nanning city. The effective data acquisition rates of radon gas and radon progeny were 99.9% and 86.7%, respectively.Results:The annual average activity concentration and equilibrium equivalent radon concentration in indoor environment were (50.9±20.7)and (15.5±10.1)Bq/m 3, both of which had the same diurnal and seasonal variation. The average annual value of equilibrium factor was 0.30±0.12, showing no obvious diurnal variation. The distribution of monthly mean value of equilibrium factor showed a similar trend to that of radon and radon progeny. The highest and the lowest value appeared in November and June, respectively, with 0.47±0.24 and 0.19±0.06. Conclusions:Due to the large variation range of monthly mean value of equilibrium factor in indoor environment, when annual effective dose of radon exposure was estimated based on radon gas concentration, attention should be paid to choose the quantity value of equilibrium factor and the uncertainty caused by the change of equilibrium factor should be considered.

The potency of an improved recombinant multi-epitope vaccine against FMDV type Asia1 was evaluated in this study .A multi-epitope gene based on FMDV type Asia1 was designed and a recombinant expression plasmid (pRE-oIgG) was constructed .The proteins ,RE-oIgG and 3D were expressed in E .coli cells and purified with Ni-NTA agarose resin by affinity chromatography .The proteins ,RE-oIgG ,3D and RE-oIgG plus 3D ,were emulsified in an oil adjuvant ISA 206 .Twenty-five female guinea pigs were randomly divided into five groups and intramuscularly vaccinated for with RE-oIgG ,3D ,RE-oIgG plus 3D ,an inactivated FMDV vaccine (type Asia1) ,and PBS .All animals were vaccinated for two times .Anti-FMDV specific an-tibodies ,neutralization antibodies ,protection potency ,and lymphoproliferation assay were detected by ELISA ,virus neutrali-zation assay ,challenge test ,and flow cytometry ,respectively .Results showed that RE-oIgG plus 3D elicited significant high-level anti-FMDV specific antibodies compared to RE-oIgG alone (P<0 .05) .All the vaccinated animals induced higher level lymphoproliferation responses in vitro except PBS .Both 3D alone and PBS produced the negligible neutralizing antibodies and anti-FMDV specific antibodies .RE-oIgG plus FMDV 3D not only elicited high levels of anti-FMDV neutralizing antibodies ,but also induced significant lymphoproliferation responses .More importantly ,RE-oIgG plus 3D conferred complete protection to guinea pigs against challenge with 1 000 GPID50 .Interestingly ,two of five vaccinated animals with 3D alone were full protected against challenge ,and other three animals significantly showed a delay of 2-3 days in the onset of clinical signs .Therefore ,we considered that RE-oIgG plus 3D induces strong humoral and cellular immune responses ,which may be used for control and prevention of FMD in the future .

To identify linear epitopes on the non-structural protein 3AB of foot-and-mouth disease virus (FMDV),BABL/c mice were immunized with the 3AB protein and splenocytes of BALB/c mice were fused with myeloma Sp2/0 cells.Two hybridoma monoclonal antibodies (mAbs) cell lines against the 3AB protein of foot-and-mouth disease virus (FMDV) were obtained,named C6 and E7 respectively.The microneutralization titer was 1∶1024 for mAb C6,and 1∶512 for E7.Both mAbs contain kappa light chains,and were of subclass IgG2b.In order to define the mAbs binding epitopes,the reactivity of these mAbs against FMDV were examined by indirect ELISA.The results showed that both mAbs can react with FMDV,but had no cross-reactivity with Swine Vesicular Disease (SVD) antigens.The titers in abdomen liquor were 1∶5×106 for C6 and 1∶2×106 for E7.In conclusion,the mAbs obtained from this study are specific for the detection of FMDV,can be used for etiological and immunological researches on FMDV,and have potential use in diagnosis and future vaccine designs.