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1.
BMC Med ; 21(1): 36, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36726141

RESUMO

BACKGROUND: Crimean-Congo hemorrhagic fever (CCHF) is a widespread disease transmitted to humans and livestock animals through the bite of infected ticks or close contact with infected persons' blood, organs, or other bodily fluids. The virus is responsible for severe viral hemorrhagic fever outbreaks, with a case fatality rate of up to 40%. Despite having the highest fatality rate of the virus, a suitable treatment option or vaccination has not been developed yet. Therefore, this study aimed to formulate a multiepitope vaccine against CCHF through computational vaccine design approaches. METHODS: The glycoprotein, nucleoprotein, and RNA-dependent RNA polymerase of CCHF were utilized to determine immunodominant T- and B-cell epitopes. Subsequently, an integrative computational vaccinology approach was used to formulate a multi-epitopes vaccine candidate against the virus. RESULTS: After rigorous assessment, a multiepitope vaccine was constructed, which was antigenic, immunogenic, and non-allergenic with desired physicochemical properties. Molecular dynamics (MD) simulations of the vaccine-receptor complex show strong stability of the vaccine candidates to the targeted immune receptor. Additionally, the immune simulation of the vaccine candidates found that the vaccine could trigger real-life-like immune responses upon administration to humans. CONCLUSIONS: Finally, we concluded that the formulated multiepitope vaccine candidates would provide excellent prophylactic properties against CCHF.


Assuntos
Vírus da Febre Hemorrágica da Crimeia-Congo , Febre Hemorrágica da Crimeia , Vacinas Virais , Humanos , Animais , Febre Hemorrágica da Crimeia/prevenção & controle , Febre Hemorrágica da Crimeia/epidemiologia , Vírus da Febre Hemorrágica da Crimeia-Congo/genética , Surtos de Doenças/prevenção & controle , Vacinação
4.
J Vet Sci ; 24(1): e15, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36726280

RESUMO

BACKGROUND: Inactivated vaccines are limited in preventing foot-and-mouth disease (FMD) due to safety problems. Recombinant virus-like particles (VLPs) are an excellent candidate for a novel vaccine for preventing FMD, given that VLPs have similar immunogenicity as natural viruses and are replication- and infection-incompetent. OBJECTIVES: The 3C protease and P1 polyprotein of type O FMD virus (FDMV) was expressed in yeast Hansenula polymorpha to generate self-resembling VLPs, and the potential of recombinant VLPs as an FMD vaccine was evaluated. METHODS: BALB/c mice were immunized with recombinant purified VLPs using CpG oligodeoxynucleotide and aluminum hydroxide gel as an adjuvant. Cytokines and lymphocytes from serum and spleen were analyzed by enzyme-linked immunosorbent assay, enzyme-linked immunospot assay, and flow cytometry. RESULTS: The VLPs of FMD were purified successfully from yeast protein with a diameter of approximately 25 nm. The immunization of mice showed that animals produced high levels of FMDV antibodies and a higher level of antibodies for a longer time. In addition, higher levels of interferon-γ and CD4+ T cells were observed in mice immunized with VLPs. CONCLUSIONS: The expression of VLPs of FMD in H. polymorpha provides a novel strategy for the generation of the FMDV vaccine.


Assuntos
Vírus da Febre Aftosa , Febre Aftosa , Doenças dos Roedores , Vacinas de Partículas Semelhantes a Vírus , Vacinas Virais , Animais , Camundongos , Saccharomyces cerevisiae , Alumínio , Adjuvantes Imunológicos , Anticorpos Antivirais
5.
Vaccine ; 41(5): 1050-1058, 2023 01 27.
Artigo em Inglês | MEDLINE | ID: mdl-36593173

RESUMO

Rift Valley Fever virus (RVFV) causes the zoonotic RVF disease, which results in substantial economic losses in livestock industries. Regular vaccination of livestock against RVF is necessary to generate long-term immunity and avoid the loss of livestock. The live attenuated vaccine based on Clone 13 virus strain has been used to reduce the negative impact of RVF disease. The vaccine strain is heat labile and requires stringent conditions for storage and handling. This research evaluated lactose and sucrose-based stabilizers coupled with lyophilisation to enhance stability of the RVF Clone 13 vaccine strain. The glass transition temperature (Tg) of the sucrose-RVF vaccine was 97.0 °C with average residual moisture of below 2 %. The lactose formulation was characterised with Tg of 83.5 °C and residual moisture of above 2 %. The RVF Clone 13 sucrose-based formulation maintained higher antigen titres during lyophilisation compared to the lactose-formulated vaccine. Cellular-mediated and humoral immunity was evaluated and compared for the two newly formulated vaccines. Pheroid® technology was also investigated as a potential adjuvant and its ability to further enhance the immunogenicity conferred by the RVF Clone 13 vaccine formulations in Merino sheep. No adverse reactions were observed following injection of the vaccine formulations in mice, guinea pigs and Merino sheep. Comparable protective humoral immune responses against RVF were obtained for all animals vaccinated with the lactose and sucrose-based stabilisers with and without the Pheroid® adjuvant. No proliferation of CD8+ and CD4+ T-cells as well as expression of IFN-γ was observed for all animals group vaccinated with Pheroid® only. Specific CD8+ IFN-γ+T-cells were expressed at higher levels compared to the CD4+ IFN-γ+T-cells in the RVF Clone 13 vaccines, suggesting that cellular immunity against RVF is through the Class I antigen presentation pathway.


Assuntos
Febre do Vale de Rift , Vírus da Febre do Vale do Rift , Vacinas Virais , Animais , Camundongos , Cobaias , Lactose , Vacinação/veterinária , Vacinas Atenuadas , Adjuvantes Imunológicos , Zoonoses , Anticorpos Antivirais
6.
Viral Immunol ; 36(1): 41-47, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36622942

RESUMO

Cache Valley virus (CVV) is a mosquito-borne bunyavirus that is enzootic throughout the new world. Although CVV is known as an important agricultural pathogen, primarily associated with embryonic lethality and abortions in ruminants, it has recently been recognized for its expansion as a zoonotic pathogen. With the increased emergence of bunyaviruses with human and veterinary importance, there have been significant efforts dedicated to the development of bunyavirus vaccines. In this study, the immunogenicity of a candidate live-attenuated vaccine (LAV) for CVV, which contains the deletion of the nonstructural small (NSs) and nonstructural medium (NSm) genes (2delCVV), was evaluated and compared with an autogenous candidate vaccine created through the inactivation of CVV using binary ethylenimine (BEI) with an aluminum hydroxide adjuvant (BEI-CVV) in sheep. Both 2delCVV and BEI-CVV produced a neutralizing antibody response that exceeds the correlate of protection, that is, plaque reduction neutralization test titer >10. However, on day 63 postinitial immunization, 2delCVV was more immunogenic than BEI-CVV. These results warrant further development of 2delCVV as a candidate LAV and demonstrate that the double deletion of the NSs and NSm genes can be applied to the development of vaccines and as a common attenuation strategy for orthobunyaviruses.


Assuntos
Vírus Bunyamwera , Vacinas Virais , Gravidez , Feminino , Animais , Humanos , Ovinos , Vírus Bunyamwera/fisiologia , Vacinas Atenuadas , Vacinas de Produtos Inativados , Anticorpos Neutralizantes
7.
BMC Vet Res ; 19(1): 18, 2023 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-36670401

RESUMO

BACKGROUND: Peste des petits ruminants (PPR), foot-and-mouth disease (FMD) and sheep pox and goat pox are three important infectious diseases that infect goats, sheep and other small ruminants. It is well-known that the prevention of three diseases rely mainly on their individual vaccines. However, the vaccines have a variety of different disadvantages, such as short duration of immunity, increasing the number of vaccinations, and poor thermal stability. The purpose of this study is to construct a recombinant goat pox virus (rGPV) capable of expressing the F gene of PPRV and the P12A3C gene of FMDV as a live vector vaccine. RESULTS: The IRES, FMDV P12A3C and PPRV F genes into the multi-cloning site of the universal transfer plasmid pTKfpgigp to construct a recombinant transfer plasmid pTKfpgigpFiP12A3C, and transfected GPV-infected lamb testis (LT) cells with liposomes and produced by homologous recombination Recombinant GPV (rGPV/PPRVF-FMDVP12A3C, rGPV). The rGPV was screened and purified by green florescence protein (GFP) and xanthine-guanine-phosphoribosyltransferase gene (gpt) of Escherichia coli as selective markers, and the expression of rGPV in LT cells was detected by RT-PCR and immunofluorescence techniques. The results showed that the virus strain rGPV/PPRVF-FMDVP12A3C containing FMDV P12A3C and PPRV F genes was obtained. The exogenous genes FMDV P12A3C and PPRV F contained in rGPV were normally transcribed and translated in LT cells, and the expression products could specifically react with PPRV and FMDV antiserum. Then, the rGPV was intradermally inoculated with goats, the animal experiments showed that rGPV/PPRVF-FMDVP12A3C could induce high levels of specific antibodies against GPV, PPRV and FMDV. CONCLUSIONS: The constructed rGPV induced high levels of specific antibodies against GPV, PPRV and FMDV. The study provides a reference for " one vaccine with multiple uses " of GPV live vector vaccine.


Assuntos
Capripoxvirus , Vírus da Febre Aftosa , Doenças das Cabras , Peste dos Pequenos Ruminantes , Vírus da Peste dos Pequenos Ruminantes , Doenças dos Ovinos , Vacinas Virais , Masculino , Ovinos , Animais , Vírus da Peste dos Pequenos Ruminantes/genética , Vírus da Febre Aftosa/genética , Capripoxvirus/genética , Anticorpos Antivirais , Vacinas Sintéticas , Peste dos Pequenos Ruminantes/prevenção & controle , Cabras
8.
Virol J ; 20(1): 13, 2023 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-36670408

RESUMO

BACKGROUND: Porcine epidemic diarrhea virus (PEDV) variant strains cause great economic losses to the global swine industry. However, vaccines do not provide sufficient protection against currently circulating strains due to viral mutations. This study traced the molecular characteristics of the most recent isolates in China and aimed to provide a basis for the prevention and treatment of PEDV. METHODS: We obtained samples from a Chinese diarrheal swine farm in 2022. Reverse transcription polymerase chain reaction and immunofluorescence were used to determine the etiology, and the full-length PEDV genome was sequenced. Nucleotide similarity was calculated using MEGA to construct a phylogenetic tree and DNASTAR. Mutant amino acids were aligned using DNAMAN and modeled by SWISS-MODEL, Phyre2 and FirstGlance in JMOL for protein tertiary structure simulation. Additionally, TMHMM was used for protein function prediction. RESULTS: A PEDV virulent strain CH/HLJJS/2022 was successfully isolated in China. A genome-wide based phylogenetic analysis suggests that it belongs to the GII subtype, and 96.1-98.9% homology existed in the whole genomes of other strains. For the first time, simultaneous mutations of four amino acids were found in the highly conserved membrane (M) and nucleocapsid (N) proteins, as well as eight amino acid mutations that differed from the vast majority of strains in the spike (S) protein. Three of the mutations alter the S-protein spatial structure. In addition, typing markers exist during strain evolution, but isolates are using the fusion of specific amino acids from multiple variant strains to add additional features, as also demonstrated by protein alignments and 3D models of numerous subtype strains. CONCLUSION: The newly isolated prevalent strain CH/HLJJS/2022 belonged to the GII subtype, and thirteen mutations different from other strains were found, including mutations in the highly conserved m and N proteins, and in the S1° and COE neutralizing epitopes of the S protein. PEDV is breaking through original cognitions and moving on a more complex path. Surveillance for PEDV now and in the future and improvements derived from mutant strain vaccines are highly warranted.


Assuntos
Infecções por Coronavirus , Vírus da Diarreia Epidêmica Suína , Doenças dos Suínos , Vacinas Virais , Suínos , Animais , Filogenia , Mutação , Vacinas Virais/genética , Aminoácidos/genética , China/epidemiologia , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/prevenção & controle , Infecções por Coronavirus/veterinária , Doenças dos Suínos/epidemiologia
11.
Int J Mol Sci ; 24(2)2023 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-36675069

RESUMO

The SARS-CoV-2 pandemic has demonstrated the need to create highly effective antivirals and vaccines against various RNA viruses, including SARS coronaviruses. This paper provides a short review of innovative strategies in the development of antivirals and vaccines against SARS coronaviruses, with a focus on antisense antivirals, oligonucleotide adjuvants in vaccines, and oligonucleotide vaccines. Well-developed viral genomic databases create new opportunities for the development of innovative vaccines and antivirals using a post-genomic platform. The most effective vaccines against SARS coronaviruses are those able to form highly effective memory cells for both humoral and cellular immunity. The most effective antivirals need to efficiently stop viral replication without side effects. Oligonucleotide antivirals and vaccines can resist the rapidly changing genomic sequences of SARS coronaviruses using conserved regions of their genomes to generate a long-term immune response. Oligonucleotides have been used as excellent adjuvants for decades, and increasing data show that oligonucleotides could serve as antisense antivirals and antigens in vaccine formulations, becoming a prospective tool for immune system tuning.


Assuntos
COVID-19 , Vacinas Virais , Humanos , Antivirais/farmacologia , Antivirais/uso terapêutico , SARS-CoV-2 , Oligonucleotídeos/farmacologia , Adjuvantes Imunológicos , Sistema Imunitário , DNA
12.
Farm. comunitarios (Internet) ; 15(1): 22-40, ene. 2023. ilus, tab, graf
Artigo em Espanhol | IBECS | ID: ibc-ADZ-647

RESUMO

Objetivos: detección, notificación y seguimiento de sospechas de reacciones adversas (RA) tras la administración de la primera dosis de la vacuna frente a la COVID-19 en usuarios de las farmacias comunitarias y su repercusión sobre la salud y vida diaria. Métodos: diseño: observacional prospectivo. Sujetos: personas vacunadas frente a la COVID-19, mayores de edad, que firmaron el consentimiento informado. Variables: número y porcentaje de participantes que presentaban al menos una RA. Número, tipo y frecuencia de posible reactividad. Repercusión en su vida diaria. El estudio fue aprobado por el CEIm-G (Exp. 2021-007).Resultados: colaboraron 10 farmacias de Pontevedra y 2 de Ourense. 781 casos, 488 (62,5 %) mujeres. Edad 56,8 (DE=17,9) años. 389 (49,8 %) en grupo de riesgo.495 (63,4 %) vacunados, 321 mujeres (65,8 %) y 174 (59,4 %) hombres refirieron al menos una RA: 236 (53,0 %) frente a Comirnaty®, 157 (82,6 %) a Vaxzevria®, 69 (66,3 %) a Spikevax® y 33 (80,5) a Janssen®.Se registraron 1.367 RA, 1,8 por persona vacunada. Las más prevalentes (el % es sobre el total de pacientes): dolor en punto de inyección 375 (48,0 %), cansancio/fatiga 170 (21,8 %), escalofríos 118 (15,1 %), cefalea 117 (15,0 %), dolor muscular 112 (14,3 %) y fiebre 98 (12,5 %). De los 495 encuestados con RA, necesitaron ayuda profesional 77 (15,6 %): del médico de familia 30 (39,0 %), 9 (11,7 %) en servicio de urgencias, 1 (1,3 %) en hospital y 37 (48,1 %) en la farmacia. A 118 (15,1 %) les impidió desarrollar su actividad diaria.Se comunicaron las RA que refirieron 264 vacunados (53,3 %).Conclusiones: el número de vacunados que manifestaron haber sufrido RA fue alto. Dolor en el punto de inyección fue la RA más prevalente. La mitad fueron atendidos en la farmacia. Aunque fueron en general leves, afectaron notablemente a su vida diaria. (AU)


Assuntos
Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Idoso , Serviços Comunitários de Farmácia , Vacinas Virais/administração & dosagem , Infecções por Coronavirus/prevenção & controle , Pneumonia Viral/prevenção & controle , Pandemias/prevenção & controle , Farmacovigilância , Estudos Prospectivos , Entrevistas como Assunto , Vacinas Virais/efeitos adversos
13.
Viruses ; 15(1)2023 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-36680186

RESUMO

Lassa fever (LF) is a rodent-borne disease that threatens human health in the sub-region of West Africa where the zoonotic host of Lassa virus (LASV) is predominant. Currently, treatment options for LF are limited and since no preventive vaccine is approved for its infectivity, there is a high mortality rate in endemic areas. This narrative review explores the transmission, pathogenicity of LASV, advances, and challenges of different treatment options. Our findings indicate that genetic diversity among the different strains of LASV and their ability to circumvent the immune system poses a critical challenge to the development of LASV vaccines/therapeutics. Thus, understanding the biochemistry, physiology and genetic polymorphism of LASV, mechanism of evading host immunity are essential for development of effective LASV vaccines/therapeutics to combat this lethal viral disease. The LASV nucleoprotein (NP) is a novel target for therapeutics as it functions significantly in several aspects of the viral life cycle. Consequently, LASV NP inhibitors could be employed as effective therapeutics as they will potentially inhibit LASV replication. Effective preventive control measures, vaccine development, target validation, and repurposing of existing drugs, such as ribavirin, using activity or in silico-based and computational bioinformatics, would aid in the development of novel drugs for LF management.


Assuntos
Febre Lassa , Vacinas Virais , Humanos , Vírus Lassa , África Ocidental/epidemiologia , Replicação Viral
15.
Bioconjug Chem ; 34(1): 269-278, 2023 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-36608270

RESUMO

The SARS-CoV-2 pandemic has highlighted the need for vaccines that are effective, but quickly produced. Of note, vaccines with plug-and-play capabilities that co-deliver antigen and adjuvant to the same cell have shown remarkable success. Our approach of utilizing a nitrilotriacetic acid (NTA) histidine (His)-tag chemistry with viral adjuvants incorporates both of these characteristics: plug-and-play and co-delivery. We specifically utilize the cowpea mosaic virus (CPMV) and the virus-like particles from bacteriophage Qß as adjuvants and bind the model antigen ovalbumin (OVA). Successful binding of the antigen to the adjuvant/carrier was verified by SDS-PAGE, western blot, and ELISA. Immunization in C57BL/6J mice demonstrates that with Qß - but not CPMV - there is an improved antibody response against the target antigen using the Qß-NiNTA:His-OVA versus a simple admixture of antigen and adjuvant. Antibody isotyping also shows that formulation of the vaccines can alter T helper biases; while the Qß-NiNTA:His-OVA particle produces a balanced Th1/Th2 bias the admixture was strongly Th2. In a mouse model of B16F10-OVA, we further demonstrate improved survival and slower tumor growth in the vaccine groups compared to controls. The NiNTA:His chemistry demonstrates potential for rapid development of future generation vaccines enabling plug-and-play capabilities with effectiveness boosted by co-delivery to the same cell.


Assuntos
COVID-19 , Vacinas Virais , Animais , Camundongos , Histidina , Ácido Nitrilotriacético , Camundongos Endogâmicos C57BL , SARS-CoV-2 , Adjuvantes Imunológicos , Antígenos , Ovalbumina
16.
Sci Rep ; 13(1): 296, 2023 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-36609424

RESUMO

Both current live, attenuated, and killed virus vaccines for bovine viral diarrhea virus (BVDV) have their limitations. Here, we report the development of a BVDV subunit vaccine by (i) the expression of a secreted form of a recombinant E2 glycoprotein using BHK21 cells and (ii) determination of the immune responses in mice. The E2 glycoprotein was modified by deletion of the C-terminal transmembrane anchor domain and fusion to a V5 epitope tag. This allowed detection using anti-V5 monoclonal antibodies together with simple purification of the expressed, secreted, form of E2 from the cell media. Furthermore, we genetically fused green fluorescent protein (GFP) linked to E2 via a Thosea asigna virus 2A (T2A) ribosome skipping sequence thereby creating a self-processing polyprotein [GFP-T2A-BVDV-E2trunk-V5], producing discrete [GFP-T2A] and [E2trunk-V5] translation products: GFP fluorescence acts, therefore, as a surrogate marker of E2 expression, BALB/c mice were inoculated with [E2trunk-V5] purified from cell media and both humoral and cellular immune responses were observed. Our antigen expression system provides, therefore, both (i) a simple antigen purification protocol together with (ii) a feasible strategy for further, large-scale, production of vaccines.


Assuntos
Vírus da Diarreia Viral Bovina , Vacinas Virais , Animais , Camundongos , Proteínas do Envelope Viral , Anticorpos Antivirais , Glicoproteínas , Proteínas Recombinantes , Vacinas de Subunidades , Diarreia
17.
Arch Virol ; 168(2): 49, 2023 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-36609880

RESUMO

Bovine viral diarrhea virus (BVDV) is a pathogen of commercial consequence in cattle. Although many modified live and killed vaccines are commercially available, their drawbacks precipitate the need for new effective vaccines. Virus-like particles (VLPs) are a safe and powerful technology used in several human and veterinary vaccines; however, it is difficult to produce large amounts of BVDV VLPs. In this study, we generated red-spotted grouper nervous necrosis virus (RGNNV) VLPs presenting the BVDV E2 protein (domain I to IIIb) of the Nose (BVDV-1) or KZ-91-CP (BVDV-2) strain by exploiting SpyTag/SpyCatcher technology. Mice immunized twice with 30 µg of RGNNV VLPs conjugated with 10 µg of E2 proteins of the Nose or KZ-91-CP strain with a 14-day interval elicited high (1:512,000 to 1:1,024,000) and moderate (1:25,600 to 1:102,400) IgG titers against E2 proteins of homologous and heterologous strains, respectively. In addition, this prime-boost regimen induced strong (1:800 to 1:3,200) and weak (~1:10) neutralization titers against homologous and heterologous BVDV strains, respectively. Our results indicate that conjugation of the E2 protein to RGNNV VLPs strongly enhances the antigenicity of the E2 protein and that RGNNV VLPs presenting the E2 protein are promising BVDV vaccine candidates.


Assuntos
Doença das Mucosas por Vírus da Diarreia Viral Bovina , Vírus da Diarreia Viral Bovina Tipo 1 , Vírus da Diarreia Viral Bovina , Vacinas de Partículas Semelhantes a Vírus , Vacinas Virais , Humanos , Bovinos , Animais , Camundongos , Anticorpos Neutralizantes , Anticorpos Antivirais , Proteínas do Envelope Viral/genética , Diarreia
18.
Arch Virol ; 168(2): 62, 2023 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-36633687

RESUMO

Foot-and-mouth disease (FMD) is a serious highly contagious viral disease affecting all cloven-hoofed animals, and outbreaks can have a severe economic impact. An inactivated heptavalent oil-adjuvanted FMD vaccine (Aphtovac-7, MEVAC) was prepared from the foot-and-mouth disease virus (FMDV) strains A-Iran05, A-Africa-IV, O-PanAsia2, O-Manisa, O-EA3, SAT-2 Gharbia, and SAT-2 LIB-12. The vaccine potency and effectiveness were evaluated in three groups of 6- to 8-month-old calves and 200 adult dairy cattle under field conditions. All animals were vaccinated with the vaccine preparation, and the three groups of calves were challenged after 28 days by intradermolingual inoculation with 104 50% tissue culture infective dose (TCID50) of FMDV serotype A, O, or SAT-2. Mock-vaccinated calves (two per group) served as unvaccinated controls during the challenge test. Adult dairy cattle were tested for seroconversion using a virus neutralization test at 30, 60, and 120 days post-vaccination. All calves displayed complete protection against challenge with the different serotypes of FMDV when compared to the control groups. Serum samples collected after the primary and booster immunizations at 30 days post-vaccination contained high titers of protective antibodies (≥ 1/32; i.e. 1.5 log10). Antibodies persisted until the end of the study period (120 days), with a peak value around 60 days post-vaccination. The heptavalent FMD vaccine preparation was found to be potent and capable of providing a protective immune response under both experimental and field conditions.


Assuntos
Doenças dos Bovinos , Vírus da Febre Aftosa , Febre Aftosa , Vacinas Virais , Animais , Bovinos , Egito , Anticorpos Antivirais , Adjuvantes Imunológicos , Vacinação/veterinária
19.
J Virol Methods ; 313: 114675, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36592741

RESUMO

Infectious bronchitis (IB) is a highly contagious viral disease of chickens caused by IB virus (IBV) that can cause substantial economic losses in the poultry industry. IBV variant infections have been continuously reported since the initial description in the 1930s. QX-like IBVs are the predominant circulating genotype globally. A homologous QX vaccine has superior protection efficacy compared with that of other available vaccines, and the combination of Massachusetts (Mass)-like and QX-like strains is being used to combat QX-like IBV infections. Inoculation of embryonated chicken eggs is the standard method for the titration of IBV, and the titer is expressed as 50% egg infectious dose (EID50). However, this method cannot effectively distinguish or quantify different genotypic strains in a mixture of different viruses, especially in the absence of neutralizing monoclonal antibodies. In this study, quantitative real-time PCR (RT-qPCR) was applied using specific primers for the QX- and Mass-like strains to quantitate IBV infection and for comparison with the conventional virus titration quantitative method. A strong positive correlation was observed between RT-qPCR cycle threshold values and the different EID50 concentrations. This method was further used to titrate bivalent IB vaccines, and the amount of individual genotype virus was determined based on specific primers. Thus, this RT-qPCR assay may be used as a highly specific, sensitive, and rapid alternative to the EID50 assay for titering IBVs.


Assuntos
Bronquite , Infecções por Coronavirus , Vírus da Bronquite Infecciosa , Doenças das Aves Domésticas , Vacinas Virais , Animais , Galinhas , Vacinas Combinadas , Reação em Cadeia da Polimerase em Tempo Real , Vacinas Atenuadas , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/prevenção & controle , Infecções por Coronavirus/veterinária , Doenças das Aves Domésticas/diagnóstico , Doenças das Aves Domésticas/prevenção & controle , Anticorpos Neutralizantes , Vírus da Bronquite Infecciosa/genética
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