# Effects of Concurrent Administration of BVDV Modified Live Viral Vaccine and RB51 on Immune Responses in Cattle

## TL;DR

This study examines how giving two vaccines together affects immune responses in cattle, finding no interference and possibly some enhancement.

## Contribution

The study provides new evidence that concurrent administration of BVDV MLV and RB51 vaccines does not interfere with immune responses.

## Key findings

- Concurrent administration of BVDV MLV and RB51 vaccines did not cause immune interference.
- There was a suggestion of enhanced IFN-γ production with concurrent vaccination.
- BVDV-specific antibody titers and IFN-γ responses were evaluated in vaccinated cattle.

## Abstract

Cell-mediated immunity is an important component of the immune response for intracellular pathogens. Live vaccines containing different pathogens are used concurrently in the field but are generally licensed individually. Concurrent administration of these vaccines has led to concerns about immune interference. The goal of this study was to characterize BVDV-specific responses to vaccination and determine the effect of concurrent Brucella abortus strain RB51 (RB51) vaccine administration. Peripheral blood mononuclear cells (PBMCs) from cattle vaccinated with a modified-live viral (MLV) vaccine containing BVDV, both RB51 and an MLV, or unvaccinated controls were utilized to evaluate antibody titers and the frequency of interferon gamma (IFN-γ) production within CD4+, CD8+ T cells, and NK cell populations via flow-cytometry. Our data demonstrated the lack of vaccine interference following concurrent administration of two common bovine MLVs and may even suggest some level of enhanced IFN-γ production with concurrent administration.