A Brazilian glycoprotein E-negative bovine herpesvirus type 1.2a (BHV-1.2a) mutant is attenuated for cattle and induces protection against wild-type virus challenge

The authors previously reported the construction of a glycoprotein E-deleted (gE-) mutant of bovine herpesvirus type 1.2a (BHV-1.2a). This mutant, 265gE-, was designed as a vaccinal strain for differential vaccines, allowing the distinction between vaccinated and naturally infected cattle. In order to determine the safety and efficacy of this candidate vaccine virus, a group of calves was inoculated with 265gE-. The virus was detected in secretions of inoculated calves to lower titres and for a shorter period than the parental virus inoculated in control calves. Twenty one days after inoculation, the calves were challenged with the wild type parental virus. Only mild signs of infection were detected on vaccinated calves, whereas non-vaccinated controls displayed intense rhinotracheitis and shed virus for longer and to higher titres than vaccinated calves. Six months after vaccination, both vaccinated and control groups were subjected to reactivation of potentially latent virus. The mutant 265gE- could not be reactivated from vaccinated calves. The clinical signs observed, following the reactivation of the parental virus, were again much milder on vaccinated than on non-vaccinated calves. Moreover, parental virus shedding was considerably reduced on vaccinated calves at reactivation. In view of its attenuation, immunogenicity and protective effect upon challenge and reactivation with a virulent BHV-1, the mutant 265gE- was shown to be suitable for use as a BHV-1 differential vaccine viru

Significance of the oligosaccharides of the porcine reproductive and respiratory syndrome virus glycoproteins GP2a and GP5 for infectious virus production

The arterivirus porcine reproductive and respiratory syndrome virus (PRRSV) contains four glycoproteins, GP2a, GP3, GP4 and GP5, the functions of which are still largely unresolved. In this study, the significance of the N-glycosylation of the GP2a and GP5 proteins of PRRSV strain LV was investigated. Both glycoproteins contain two predicted N-glycosylation sites that are highly conserved between North American-type and European-type PRRSV. Using site-directed mutagenesis, single and double mutant full-length PRRSV cDNA clones were generated. After analysing the expression of the mutant proteins and the actual use of the four putative glycosylation sites in the wild-type proteins, the production of mutant virus particles and their infectivities were investigated. The results showed that the N-linked glycans normally present on the GP2a protein are not essential for particle formation, as is the oligosaccharide attached to N53 of the GP5 protein. In contrast, the oligosaccharide linked to N46 of the GP5 protein is strongly required for virus particle production. The specific infectivities of the mutant viruses were investigated by comparing their infectivity-per-particle ratios with that of wild-type virus. The results showed that the lack of either one or both of the N-linked oligosaccharides on GP2a or of the oligosaccharide attached to N53 of GP5 did not significantly affect the infectivities of the viruses. In contrast, the two recombinant viruses lacking the oligosaccharide bound to N46 exhibited a significantly reduced specific infectivity compared with the wild-type virus. The implications of the differential requirements of the modifications of GP2a and GP5 for PRRSV assembly and infectivity are discusse

Antigenic and molecular characterization of eight samples of Aujeszky's disease virus isolated in the state of Rio Grande do Sul, Brazil, in 2003

Pseudorabies or Aujeszky's disease (AD), caused by pseudorabies virus (PRV) is a major concern in swine production. In the state of Rio Grande do Sul, Brazil, AD was only detected in 1954, in cattle. In 2003 two outbreaks of encephalitis occurred on the northern region of the state, close to the border with the state of Santa Catarina. Pseudorabies virus (PRV) was isolated from distinct farms within the region and subjected to antigenic and genomic analyses. These isolates were compared with prototype strains NIA-3 and NP. Antigenic characterization with a panel of monoclonal antibodies (Mabs) directed to viral glycoproteins (gB, gC, gD and gE-,) was performed by an imunoperoxidase monolayer assay (IPMA) on infected cell monolayers. Genomic characterization was carried out by restriction enzyme analysis (REA) of the whole DNA viral genome with Bam HI. The antigenic profile of the eight isolates from Rio Grande do Sul as well as strains NIA-3 and NP were similar. REA analysis revealed that all isolates from Rio Grande do Sul displayed a genomic type II arrangement, a genotype often found in other outbreaks of AD previously reported in other Brazilian states. The results obtained suggest that the eight isolates examined here were similar

Live recombinant BHV/BRSV vaccine

The present invention refers to synthetic Bovine Respiratory Syncytium virus genes. Also the invention relates to live attenuated Bovine Herpesvirus recombinants carrying such synthetic genes. Furthermore, the invention relates to vaccines based on these live attenuated recombinants, for the protection of cattle against both Bovine herpesvirus infection and against Bovine Respiratory Syncytium virus infection. Also the invention relates to methods for the preparation of such live attenuated recombinants and to methods for the preparation of such vaccines. Furthermore, the invention relates to live Bovine herpesvirus recombinant particles carrying a class II membrane glycoprotein and to live Bovine herpesvirus recombinants carrying a heterologous gene fused to a class II membrane glycoprotein membrane anchor, to vaccines based thereon, and to methods for the preparation of such recombinants, such particles and such vaccines

Advances in development and evaluation of bovine herpesvirus 1 vaccines

This review deals with conventional and modern bovine herpesvirus 1 (BHV1) vaccines. Conventional vaccines are widely used to prevent clinical signs of infectious bovine rhinotracheitis. The use of conventional vaccines, however, does not appear to have resulted in reduction of the prevalence of infection. Novel BHV1 marker vaccines comprise either mutants with a deletion in one of the non-essential genes, or subunit vaccines that contain one or more glycoproteins. These marker vaccines can be used in conjunction with companion diagnostic tests to differentiate between infected and vaccinated cattle. Their efficacy has been evaluated in vaccination-challenge experiments, transmission experiments and in field trials. The results demonstrate that the marker vaccines can contribute to the eventual eradication of BHV1. However, there remains room for improvement of BHV1 marker vaccines

Bovine polynucleotide vaccine for the intradermal route

Disclosed and claimed is the use of a liquid jet intradermal administration apparatus that administers a composition: without a needle; and in the epidermis, dermis and/or hypodermis, such as a Pigjet apparatus, for administering bovine vaccines or immunogenic compositions, especially bovine plasmid vaccines or immunogenic compositions. Accordingly, the invention involves bovine immunogenic or vaccine compositions in such an apparatus, and methods for vaccinating bovines or for inducing an immunogenic response in bovines employing such an apparatus, as well as the apparatus containing bovine immunogenic or vaccine compositions

Advances in development and evaluation of bovine herpesvirus 1 vaccines

This review deals with conventional and modern bovine herpesvirus 1 (BHV1) vaccines. Conventional vaccines are widely used to prevent clinical signs of infectious bovine rhinotracheitis. The use of conventional vaccines, however, does not appear to have resulted in reduction of the prevalence of infection. Novel BHV1 marker vaccines comprise either mutants with a deletion in one of the non-essential genes, or subunit vaccines that contain one or more glycoproteins. These marker vaccines can be used in conjunction with companion diagnostic tests to differentiate between infected and vaccinated cattle. Their efficacy has been evaluated in vaccination-challenge experiments, transmission experiments and in field trials. The results demonstrate that the marker vaccines can contribute to the eventual eradication of BHV1. However, there remains room for improvement of BHV1 marker vaccines