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@#Objective To analyze the safety of children of different ages vaccinated with measles,mumps and rubella combined attenuated live vaccine(MMR in brief)/measles and rubella combined attenuated live vaccine(MR in brief)in Jilin Province from 2015 to 2022.Methods The actual vaccination data of MMR and MR from January 1,2015 to December 31,2022 were collected through the Jilin information management system for immunization programming,and all AEFI case information reported after vaccination with MMR and MR in this period was collected through the national adverse event following immunization(AEFI) monitoring and reporting system.The incidence rates of AEFI reports were compared among8-month-old children vaccinated with the first dose of MMR(MMR 8 group) and MR(MR8 group),18-month-old children vaccinated with the first dose of MMR(vaccinated with MR at 8 months old,MMR18-1 group) and the second dose of MMR(vaccinated with the first dose of MMR at 8 months old,MMR18-2 group) to preliminarily evaluate the safety of children vaccinated with MMR and MR at different ages.Results The reported incidence of AEFI in MMR8,MR8,MMR18-1 and MMR18-2 groups were 374.41/100 000,350.81/100 000,101.70/100 000 and 104.91/100 000,respectively,with significant difference among the four groups(χ~2=1 145.47,P=0.00);There was no significant difference between MMR8 and MR8,as well as MMR18-1 and MMR18-2 groups(χ~2=3.780 and 0.194,respectively,each P> 0.05);There were significant differences between MMR8 and MMR18-1,MMR8 and MMR18-2,as well as MR8 and MMR18-1groups(χ~2=920.440,412.110 and 1 021.120,respectively,each P=0.00).Most of the adverse reactions were general reactions,mainly fever,local redness and induration;A few were abnormal reactions,which were mainly allergic reactions(rash,papules,urticaria,etc.).Only one case of coincidence was reported in MMR8 group,and no psychogenic reaction,vaccine quality accident and vaccination accident occurred.All AEFI turned out to be improved or cured.Conclusion The differences of AEFI reported incidence of 8-month-old children vaccinated with MMR and MR were all small,and the difference of AEFI reported incidence of 18-month-old children vaccinated with the second dose of MMR was small regardless of the initial vaccination with MMR or MR.It is safe to use MMR instead of MR for the first vaccination in8-month-old children.
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@#Human respiratory syncytial virus(hRSV)is one of the main pathogens that cause lower respiratory tract infection in infants and the elderly.hRSV genome contains 10 genes with a full length of 15 222 bp,encoding 11 proteins(9structural proteins and 2 non-structural proteins).Different proteins play different roles in the pathogenesis of hRSV.With the in-depth research on the biological and structural characteristics of hRSV,various types of hRSV vaccines have been developed,making rapid progress.For example,hRSV attenuated live vaccine hRSV ?NS2/?1313/I1314L has entered Phase II clinical trial,and hRSV subunit protein vaccine Pre-F-GCN4t has entered Phase III clinical trial.In this paper,the biological characteristics of hRSV and the types of hRSV vaccines with rapid progress are reviewed so as to provide a reference for the development of hRSV vaccines in China.
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ObjectiveTo evaluate the dosage effect of measles， mumps and rubella combined attenuated live vaccine （MMR） vaccination on seroprevalence of mumps. MethodsA cross-sectional study was conducted among people in Changning District of Shanghai aged 1 month to 19 years old （n=1 816） in Mar.－Sep. 2017. Blood samples were analyzed for mumps antibodies using enzyme-linked immunosorbent immunoglobulin G （IgG） assays. ResultsMumps antibody seropositivity was 94.59% in 2 years old children and maintained at 98.18%-100.00% from 4 to 9 years old. The seropositivity began to decrease since 10 years， and it was 88.33% （95%CI： 81.20%-93.47%） at age of 12 years. In 12-19 years age group， individuals with 3 doses of mumps-containing vaccines had the highest seropositivity （93.88%） and individuals with 1 or 0 doses had the lowest seropositivity （68.75%）. ConclusionTwo-dose MMR immunization in Shanghai induces a sharp increase in mumps antibody levels in the corresponding age groups. The antibody levels decline gradually with time since the second dose. Vaccine dosage is positively associated with mumps IgG seropositivity and geometric mean concentrations （GMC） in 12-19 years old.
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ObjectiveTo evaluate the dosage effect of measles， mumps and rubella combined attenuated live vaccine （MMR） vaccination on seroprevalence of mumps. MethodsA cross-sectional study was conducted among people in Changning District of Shanghai aged 1 month to 19 years old （n=1 816） in Mar.－Sep. 2017. Blood samples were analyzed for mumps antibodies using enzyme-linked immunosorbent immunoglobulin G （IgG） assays. ResultsMumps antibody seropositivity was 94.59% in 2 years old children and maintained at 98.18%-100.00% from 4 to 9 years old. The seropositivity began to decrease since 10 years， and it was 88.33% （95%CI： 81.20%-93.47%） at age of 12 years. In 12-19 years age group， individuals with 3 doses of mumps-containing vaccines had the highest seropositivity （93.88%） and individuals with 1 or 0 doses had the lowest seropositivity （68.75%）. ConclusionTwo-dose MMR immunization in Shanghai induces a sharp increase in mumps antibody levels in the corresponding age groups. The antibody levels decline gradually with time since the second dose. Vaccine dosage is positively associated with mumps IgG seropositivity and geometric mean concentrations （GMC） in 12-19 years old.
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Objective To analyze the loss coefficient of bivalent live attenuated oral polio vaccine（bOPV) in Hongshan District, and understand the causes and influencing factors, and to provide a basis for scientifically formulating vaccine use plans and regulating vaccine management. Methods Using the data of Hubei Province Immunization Planning Information System and Hongshan District Vaccination Storage and Management System, a special questionnaire was designed to understand the vaccination and use of bOPV in various immunization units in Hongshan District. A descriptive statistical analysis method was used to calculate the loss coefficient. Results The bOPV loss coefficient of 25 vaccination units in Hongshan District was 1.69. The difference of the loss coefficient between the out-patient clinics of the District Health and Family Planning Committee（1.35）and the community clinics undertaken by large hospitals (2.01）was statistically significant. The difference of the loss coefficient between the inoculation once a week（1.57）and 2-6 times per week（1.94）was statistically significant. In terms of vaccine-disabled time, the two groups of 4 hours had different calculated loss coefficients 1.86 and 1.61, respectively, and the difference was statistically significant. Multivariate regression analysis of the factors related to the loss coefficients found that different outpatient attributes had a greater impact on the loss coefficient than the inoculation cycle and the number of inoculation stations. The loss coefficient for 2016 and 2017 was 2.09 and 1.75, respectively. The difference was statistically significant. Conclusion The management and use of live attenuated bivalent polio vaccine in Hongshan District was relatively standardized. The vaccine loss can by further reduced by strengthening supervision and assessment, setting up centralized vaccination and standardizing publicity and training.
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Objective@#To analyze the surveillance of adverse event following immunization (AEFI) among 8-month-old children in Jiaxing who received measles, mumps and rubella combined attenuated live vaccine (MMR) or measles and rubella combined attenuated live vaccine (MR) , so as to provide support for the adjustment of vaccine immunization strategy.@*Methods @#The AEFI information of MR (December 1, 2016 to April 30, 2018) and MMR (December 1, 2018 to April 30, 2020) was collected through National AEFI Monitoring Information Management System to compare the incidence, clinical features, occurred time of AEFI as well as combined vaccination.@*Results@#Totally 94 287 doses of MR and 79 994 doses of MMR were administered, 145 and 156 cases of AEFI were reported, and the incidence rate was 15.38/10 000 after MR vaccination, which was lower than 19.50/10 000 after MMR vaccination (P<0.05). Most reported AEFI were abnormal reactions, with 93 cases (11.63/10 000) after MR vaccination and 101 cases (10.71/10 000) after MMR vaccination, among which 72 cases (7.64/10 000) and 76 cases (9.50/10 000) respectively had allergic rash. The AEFI cases mainly occurred less than one day after vaccination, with 113 cases (77.93%) after MR vaccination and 125 cases (80.13%) after MMR vaccination. Most cases of AEFI were vaccinated with Japanese encephalitis attenuated live vaccine (JEV), with 103 cases (71.03%) after MR vaccination and 102 cases (65.38%) after MMR vaccination.@*Conclusions@#The MMR is safety for 8-month-old children in Jiaxing. Most AEFI cases had abnormal reactions, occur within one day after vaccination, and are vaccinated with JEV.
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As the COVID-19 pandemic is intensifying globally, more and more people are pinning their hopes on the development of vaccines. At present, there are many research teams who have adopted different vaccine technology routes to develop 2019-nCoV vaccines. This article reviews and analyzes the current development and research status of 2019-nCoV vaccines in different routes, and explores their possible development in the future.
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Humains , Betacoronavirus , Infections à coronavirus , Pandémies , Pneumopathie virale , Vaccins antiviraux , Utilisations thérapeutiquesRésumé
The yellow fever (YF) attenuated live vaccine 17D is one of the oldest attenuated live vaccines and historically well known for its good immunogenicity and safety. Because of the high safety of YF attenuated live vaccine 17D, its genome is used as the backbone of recombinant vaccines that deliver flavivir-uses or non-associated antigens. With the prevalence of YF, the demand for YF attenuated live vaccines is increasing. At present, there is insufficient supply of YF attenuated live vaccines in the world. Much atten-tion has been paid to YF attenuated live vaccines. In this paper, the quality, use and prospect of YF attenu-ated live vaccine are reviewed.
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Objective:To develop a host-vector balanced lethal system of attenuated Salmonella typhinurium secreted effector K1 mutant,and an live vaccine vector which stably carries exogenous genes. Methods:We constructed SL1344ΔsseK1Δasd mutant strain by recombinant suicide plasmid( pREΔasd) ,and screened by two-step method,transformed pYA3493 plasmid containing the asd gene without resistance electric into the mutant strain of SL1344ΔsseK1Δasd, then the recombinant strain SL1344ΔsseK1Δasd (pYA3493) was constructed successfully. Results:The results of PCR and sequencing showed that SL1344ΔsseK1Δasd(pYA3493)was constructed successfully. Further studies had shown that the serotype of the recombinant strain was identical to the parent SL1344ΔsseK1 and wild SL1344 strains,and the mutant was stable with the recombinant Δasd gene in vitro. It was found that the re-combinant strain had displayed identical growth profile and biochemical characteristics compared with the parent SL1344ΔsseK1 strain and wild SL1344 strain. The oral challenge of bacteria in mice revealed that LD50 of the recombinant strain was 5. 24×108 CFU,and the toxicity reduced to about 0. 048%;the immunoprotective effect assay showed that the protection rate infected with wild strain of Salmonella typhimurium was 62. 5% on the 17th day post-immunization,which was identical to the parent SL1344ΔsseK1. Conclusion:These results show that the secreted effector K1 gene deleted mutant host-vector balanced lethal system of Salmonella typhimurium SL1344 strain has been successfully constructed,and genetic stability,significantly reduced virulence,which has laid a foundation for developing potential oral live vaccin vector to express foreign genes.
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Objective:To develop a host-vector balanced lethal system of attenuated Salmonella typhinurium secreted effector K1 mutant,and an live vaccine vector which stably carries exogenous genes. Methods:We constructed SL1344ΔsseK1Δasd mutant strain by recombinant suicide plasmid( pREΔasd) ,and screened by two-step method,transformed pYA3493 plasmid containing the asd gene without resistance electric into the mutant strain of SL1344ΔsseK1Δasd, then the recombinant strain SL1344ΔsseK1Δasd (pYA3493) was constructed successfully. Results:The results of PCR and sequencing showed that SL1344ΔsseK1Δasd(pYA3493)was constructed successfully. Further studies had shown that the serotype of the recombinant strain was identical to the parent SL1344ΔsseK1 and wild SL1344 strains,and the mutant was stable with the recombinant Δasd gene in vitro. It was found that the re-combinant strain had displayed identical growth profile and biochemical characteristics compared with the parent SL1344ΔsseK1 strain and wild SL1344 strain. The oral challenge of bacteria in mice revealed that LD50 of the recombinant strain was 5. 24×108 CFU,and the toxicity reduced to about 0. 048%;the immunoprotective effect assay showed that the protection rate infected with wild strain of Salmonella typhimurium was 62. 5% on the 17th day post-immunization,which was identical to the parent SL1344ΔsseK1. Conclusion:These results show that the secreted effector K1 gene deleted mutant host-vector balanced lethal system of Salmonella typhimurium SL1344 strain has been successfully constructed,and genetic stability,significantly reduced virulence,which has laid a foundation for developing potential oral live vaccin vector to express foreign genes.
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Objective To evaluate the safety and immunogenicity of one booster dose of inactivated hepatitis A vaccine in young adults.Methods The subjects were selected from participants in the clinical trial of immunogenicity of inactivated and attenuated live hepatitis A vaccine in young adults.Eligible subjects were those who had received one dose of inactivated or attenuated hepatitis A vaccine,could be contacted and were sero-negative before primary vaccination.All qualified subjects were immunized with one booster dose of inactivated hepatitis A vaccine.The blood samples were collected before booster dose vaccination and 28 days after the immunization.Anti-HAV antibody titer ≥20 mIU/ml was considered to be sero-protected against hepatitis A virus.Results The GMCs in the inactivated HAV vaccine group and attenuated live vaccine group before booster dose vaccination were 70.80 mIU/ml and 50.12 mIU/ml,respectively,and the sero-protection rates were 94.7％ and 65.0％,respectively.After the vaccination of the booster dose,the sero-protection rates in both groups were 100.0％,and the GMCs were 2 816.09 mIU/ml and 2 654.55 mIU/ml,respectively.Conclusion The GMCs and sero-protection rates of anti-HAV antibody in young adults declined after three years of the primary vaccination.However,the higher GMC and sero-protection rate were observed in the inactivated vaccine group than in the attenuated live vaccine group.Significant increases of GMC levels were observed in both groups after one booster dose vaccination.
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Objective To evaluate the safety and immunogenicity of one booster dose of inactivated hepatitis A vaccine in young adults.Methods The subjects were selected from participants in the clinical trial of immunogenicity of inactivated and attenuated live hepatitis A vaccine in young adults.Eligible subjects were those who had received one dose of inactivated or attenuated hepatitis A vaccine,could be contacted and were sero-negative before primary vaccination.All qualified subjects were immunized with one booster dose of inactivated hepatitis A vaccine.The blood samples were collected before booster dose vaccination and 28 days after the immunization.Anti-HAV antibody titer ≥20 mIU/ml was considered to be sero-protected against hepatitis A virus.Results The GMCs in the inactivated HAV vaccine group and attenuated live vaccine group before booster dose vaccination were 70.80 mIU/ml and 50.12 mIU/ml,respectively,and the sero-protection rates were 94.7％ and 65.0％,respectively.After the vaccination of the booster dose,the sero-protection rates in both groups were 100.0％,and the GMCs were 2 816.09 mIU/ml and 2 654.55 mIU/ml,respectively.Conclusion The GMCs and sero-protection rates of anti-HAV antibody in young adults declined after three years of the primary vaccination.However,the higher GMC and sero-protection rate were observed in the inactivated vaccine group than in the attenuated live vaccine group.Significant increases of GMC levels were observed in both groups after one booster dose vaccination.
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Objective To analyze the characteristics of adverse reactions for varicella attenuated live vaccine (VarV) in Henan Province from 2011 to 2016, in order to evaluate the immunization safety related to VarV. Methods The adverse reaction data and vaccination doses of VarV in Henan Province from 2011 to 2016 were collected through the China Information Management System for Immunization Programming. The descriptive methodology was used for data analysis. Results A total of 686 adverse reactions cases were reported in Henan Province from 2011 to 2016, and the average reported incidence rate was 16.89 per 100000 dose. The ratio of male to female was 1.14:1, and 80.61% cases occurred between 1 and 2 years old, and the reported incidence rate was 13.62 per 100000 dose. And 32.80% cases were reported from April to June, and the reported incidence rate was 5.54 per 100000 dose. The cases were mainly concentrated in Zhengzhou, Luoyang, Zhoukou and Xinyang. Most cases occurred after the first dose and within 1 d after vaccination. The main diagnoses of adverse reactions were fever, local swelling, indurations and transient anaphylactic disorders. The reported incidence rate of anaphylactic shock and fever convulsion were 0.37 per 100000 dose and 0.12 per 100000 dose respectively. All cases were recovered or got better. Conclusion The safety of VarV was good in Henan Province. However, the surveillance should focus on the anaphylactic shock and fever convulsion and other serious rare adverse reaction.
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Objective: To develop an oral live vaccine vector which stably carries exogenous genes.Methods:SL1344ΔsipBΔasd host-vector balanced lethal system was constructed by the method of recombinant suicide plasmid-mediated allelic exchange on the basis of attenuated Salmonella typhinurium SL1344ΔsipB.Then,the biological characteristics of SL1344ΔsipBΔasd was analyzed.Results:The results showed that the mutant was stabile with the Δasd gene in vitro;the serotype and growth rate of SL1344ΔsipBΔasd strain was almost same as the parent SL1344ΔsipB and SL1344 strain.And the mutant strains remain swim ming zones.Virulence test in mice showed that the virulence of SL1344ΔsipBΔasd which carried complementary plasmid pYA3493 by electro-transformation decreased by 1.4%compared with SL1344.Conclusion: These results showed that the SL1344ΔsipBΔasd mutant was successfully constructed.It is likely that this mutant should be used as a live vector to express foreign genes.
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Objective To evaluate the effectiveness and safety of varicella attenuated live vaccine ( VarV) produced by A Co. Ltd. Methods We selected 3 provinces in China and enrolled 15 002 children aged 3-<11 in this random, multicenter study. Participants were randomly divided into two groups: the ex-perimental group and the control group. Every varicella case was collected and recorded to calculate the vac-cine efficacy. Vaccine safety was assessed by means of spontaneous report and regular follow-up visits. Re-sults During the observation period, the incidence of varicella was 0. 147% in the experimental group and 1. 155% in the control group (P<0. 001). The vaccine efficacy was 87. 27%. The adverse reaction rate af-ter vaccination was lower than the rates reported in other literatures. Conclusion The VarV produced by A Co. , Ltd. in China was effective and safe in preventing varicella.
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In order to develop a recombinant attenuated Salmonella typhimurium as oral live vaccine vector, we constructed recombinant plasmid pYA-sopENt100 by replacing the trc promoter with the sopE promoter and secretion signal sequence sopENt100 of Salmonella typhimurium on the basis of plasmid pYA3493. Then, the complementary plasmid pYA-sopENt100 was transformed into ΔcrpΔasdSL1344 by electroporation to generate attenuated Salmonella typhimurium type III secretion system ΔcrpΔasdSL1344 (pYA-sopENt100). We further characterized ΔcrpΔasdSL1344 (pYA-sopENt100). We also constructed a recombinant strain ΔcrpΔasdSL1344 (pYA-sopENt100-egfp) that harbored the reporter gene-enhanced green fluorescent protein (egfp) gene. Vero cells were infected with ΔcrpΔasdSL1344 (pYA-sopENt100-egfp) and the ability of delivery foreign antigens was tested via Western blotting analysis. The results of PCR, enzyme digestion and sequencing showed that the ΔcrpΔasdSL1344 (pYA-sopENt100) type III secretion system was constructed successfully. The serotype of ΔcrpΔasdSL1344 (pYA-sopENt100) was identical to ΔcrpΔasdSL1344 and SL1344. Compared with wild strain SL1344, the biochemical characteristics of ΔcrpΔasdSL1344 (pYA-sopENt100) had obvious change, but it was basically the same with ΔcrpΔasdSL1344. The growth speed was much slower than that of the wild strain SL1344. The chicken virulence test (LD₅₀) showed that the virulence of ΔcrpΔasdSL1344 (pYA-sopENt100) was 7×10⁴ times lower than SL1344. In addition, we observed the 37 kDa SopENt100-egfp protein in the cultured supernatant of ΔcrpΔasdSL1344 (pYA-sopENt100-egfp) strain by Western blotting analysis. However, both the 37 kDa SopENt100-egfp protein and 27 kDa EGFP protein were detected in ΔcrpΔasdSL1344 (pYA-sopENt100-egfp)-infected Vero cells. These results demonstrated that the recombinant Salmonella typhimurium type III secretion system ΔcrpΔasdSL1344 (pYA-sopENt100) was successfully constructed, and it should be used as a live vaccine vector for expressing foreign genes.
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Animaux , Souris , Protéines bactériennes , Génétique , Chlorocebus aethiops , Plasmides , Régions promotrices (génétique) , Salmonella typhimurium , Génétique , Systèmes de sécrétion de type III , Génétique , Vaccins atténués , Génétique , Cellules Vero , VirulenceRésumé
OBJECTIVE:To observe the safety and immunological effects of Measles-mumps-rubella(MMR)attenuated live at-tenuated vaccine in children. METHODS:300 children aged 8-12 months receiving inoculation were selected from Changsha Hospi-tal for Maternal and Child Health Care during Jan. 2015-Apr. 2016 to observe safety and immunological effects. Those children were divided into MMR group,measles vaccine group,mumps vaccine group and rubella vaccine group according to vaccine type, with 75 cases in each group. The occurrence of ADR in 72 h were compared among 4 groups after inoculation;venous blood of chil-dren was collected before vaccination and 5 months after vaccination,and the antibody positive test was carried out by micro coagu-lation inhibition (HI) test;HI antibody titer was recorded after immunization,and positive rate and genometric meantiter(GMT) were calculated. RESULTS:The incidence of ADR in 4 groups were 9.33%,8.00%,8.00% and 10.67%,respectively. No local ADR was found in 4 groups;among systemic ADR,the incidence of fever was higher than that of other clinical manifestations,be-ing 4.00%,4.00%,4.00% and 5.33%;there was no statistical significance in the incidence of ADR among 4 groups(P>0.05). Measles,mumps and rubella antibody positive rates of MMR group were 100%,92.00% and 100%,respectively;antibody posi-tive rates of measles vaccine group,mumps vaccine group and rubella vaccine group were 100%,85.33% and 100%,respective-ly;there was no statistical significance in same antibody positive rate among 4 groups(P>0.05). GMT of measles in MMR group and measles vaccine group were 1∶41 and 1∶27,that of mumps in MMR group and mumps vaccine group were 1∶6.3 and 1∶6.2, there was no statistical significance (P>0.05);GMT of rubella in MMR group and rubella vaccine group were 1∶320 and 1∶849, with statistical significance (P<0.05). CONCLUSIONS:Compared to traditional single vaccine,MMR dose not increase the inci-dence of ADR and not influence positive rate,but GMT of rubella increases significantly,to which should be paid attention.
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Enterovirus 71 (EV71) is one of the primary causative agents of hand, foot and mouth disease in children and closely associated with severe neurological complications and even deaths.EV71 outbreaks have occurred throughout the Asia-Pacific region since 1990s, posing global public health threat;however, no specific therapeutic strategy exists for severe EV71 infection.Several inactivated vaccine products have entered or finished the clinical trial stage, and some novel vaccine candidates, including live attenuated, subunit, and virus-like particle, show great potential for further develop-ment.This review summarizes the present situation and progress in the development of EV71 vaccines.
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Objective:In order to develop an oral live vaccine vector of swine that can stably carry exogenous genes.Methods:Mutant ΔcrpΔcyaΔasdC78-1 was constructed by the method of suicide plasmid pREasd-mediated bacteria homologous recombination on the basis of attenuated Salmonella choleraesuisΔcrpΔcyaC78-1.Complementary plasmid pYA3493 with asd was electrotransformed into the mutant,and thenΔcrpΔcyaΔasdC78-1(pYA3493) host-vector balanced lethal system was constructed.Its biological characteristics were analyzed further.Results:The results of PCR and sequencing showed thatΔcrpΔcyaΔasdC78-1(pYA3493) was constructed suc-cessfully.Biological characteristics showed that the serotype of ΔcrpΔcyaΔasdC78-1(pYA3493) was identical to ΔcyaΔasdC78-1 and vaccine strain C500 and it can stably carry theΔasd gene in vitro;its growth speed was a little slower than ΔcrpΔcyaC78-1 strain,but both of their growth speeds were significantly slower than vaccine strain C500;the biochemical characteristics of ΔcrpΔcyaΔasdC78-1 ( pYA3493 ) were basically the same with ΔcrpΔcyaC78-1 strain.Oral virulence test in mice showed that the virulence ofΔcrpΔcyaΔasdC78-1 ( pYA3493 ) was similar with ΔcrpΔcyaC78-1, but its median lethal dose is 412 times of vaccine strain C500.Conclusion:These results demonstrated that attenuated Salmonella choleraesuisΔcrpΔcyaΔasdC78-1(pYA3493) strain had the potential to be used as an oral live vaccine vector for expressing foreign genes efficiently.
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To develop a live vaccine strain against fowl typhoid and paratyphoid caused by Salmonella serovar Gallinarum biovar Gallinarum (Salmonella Gallinarum) and Salmonella serovar Enteritidis (Salmonella Enteritidis), respectively, several nalidixic acid resistant mutants were selected from lipopolysaccharide (LPS) rough strains of Salmonella Gallinarum that escaped from fatal infection of a LPS-binding lytic bacteriophage. A non-virulent and immunogenic vaccine strain of Salmonella Gallinarum, SR2-N6, was established through in vivo pathogenicity and protection efficacy tests. SR2-N6 was highly protective against Salmonella Gallinarum and Salmonella Enteritidis and safer than Salmonella Gallinarum vaccine strain SG 9R in the condition of protein-energy malnutrition. Thus, SR2-N6 may be a safe and efficacious vaccine strain to prevent both fowl typhoid and paratyphoid.