Acute and persistent herpes and pestivirus infections of cattle: the risk of spread during fertilization

Every year, a significant number of breeding animals are imported into the Russian Federation from regions with an ambiguous epizootic situation on pesti- and herpesvirus infections. In 2015‒2018 ruminant viruses that are new to the Russian Federation and some neighboring countries were identified. Among them: Bovine herpesvirus type 5, pestiviruses ― pathogens of Border disease and Hobi-like viral infection, new subtypes of BVDV, etc. The introduction of Bovine herpesvirus type 5 in the north-west region of the country has been traced. Relatively small differences in the antigens and structure of the virus genomes significantly complicate the differential diagnosis of respiratory, gastrointestinal and reproductive diseases. As a result, the effectiveness of anti-epizootic measures, in particular vaccination, is significantly reduced. It is possible that the increased incidence of cattle in recent years of infectious bovine rhinotracheitis in the Siberian region is due to the Bovine herpesvirus type 5 (BoHV-5) due to its introduction with breeding animals or genetic material (semen, eggs). According to the OIE recommendations, several tests should be used to differentiate antigenically and genetically close pathogens: PCR, genome sequencing, serological tests using monoclonal antibodies, etc.

Saccharomyces boulardii modulates and improves the immune response to Bovine Herpesvirus type 5 Vaccine

ABSTRACT There have been significant efforts towards the development of more efficient vaccines for animal health. A strategy that may be used to improve vaccine efficacy is the use of probiotics to enhance the immune response of the host, leading to increased immunogenicity of antigen preparations. Bovine herpesvirus 5 (BoHV-5) is an example of an important animal pathogen for which vaccines have provided only limited protection. In this study, we examined the use of the probiotic Saccharomyces boulardii (Sb) as a potential adjuvant to improve vaccine efficiency. We found that the supplemented animals exhibited an enhanced systemic IgG antibody response toward a Th1 response in favor of IgG2a and increased mRNA expression levels of the cytokines IFN-y, IL-12, IL-17 and IL-10 in the spleen. These results suggest that Sb supplementation may provide a promising means for improving the efficiency of vaccines, particularly those that rely on a cell-mediated immune response.

Bacillus toyonensis improves immune response in the mice vaccinated with recombinant antigen of bovine herpesvirus type 5

Probiotics modulate the immune response and can increase the effectiveness of vaccines. Bacillus toyonensis is widely used as a probiotic in animal feed. The aim of this study was to assess the effects of B. toyonensis administration on the immune response to an experimental recombinant vaccine against bovine herpesvirus type 5 (BoHV-5) in mice. Mice were vaccinated with BoHV-5 recombinant glycoprotein D and supplemented with the probiotic B. toyonensis in two regimes: one group received the probiotic only during seven days prior to the initial vaccination while the second group was given the probiotic throughout the experimental period of seven weeks. Animals supplemented with probiotic B. toyonensis in two regimes showed an increase in total immunoglobulin (Ig)G, IgG1 and IgG2a levels in serum, in addition to higher titres of antibodies capable of neutralising the BoHV-5 virus than non-supplemented animals (P<0.05). Splenocytes from the supplemented mice had higher mRNA transcription levels of cytokines interleukin (IL)-4 and IL-12. These results show that the use of this probiotic may significantly contribute to the response elicited by recombinant vaccines, especially those that rely on increasing antibody and cell-mediated immune responses for efficacy. Further, the data support an immunomodulatory effect for probiotic B. toyonensis and imply that enhance effect on the immune response against a BoHV-5 recombinant vaccine in mice.