Speakers - 2026

Mycoplasma bovis (M. bovis) and bovine alphaherpesvirus 1 (BoAHV-1) are two major infections that seriously impair cattle's reproductive and respiratory systems. We developed an attenuated and marker M. bovis-BoAHV- 1 combined vaccine based on the M. bovis HB150 and BoHV-1 gG-/tk- strains in our earlier work. This study evaluated its immunogenicity against different antigens and efficacy in protecting cattle against diverse BoAHV-1 genotypes. After immunization, all vaccinated cattle had a normal rectal temperature and mental status without respiratory symptoms. CD4+, CD8+, and CD19+ cells significantly increased in immunized cattle and induced higher humoral and cellular immune responses, and the expression of key cytokines such as IL-4, IL-12, TNF-α, and IFN- γ can be promoted after vaccination. Gross lesions and microscopic pathological examination of lung tissue revealed the mildest damage in vaccinated calves. Virus shedding results from nasal swabs indicated that the combined vaccine reduced M. bovis bacterial shedding by three titers and BoAHV-1 viral shedding by two titers in vaccinated cattle compared to unvaccinated calves; additionally, the BoAHV-1 viral load in the trigeminal ganglia of vaccinated individuals was also approximately two titers lower than in unvaccinated individuals. In further experiments, when the vaccinated cattle were challenged with either the BoAHV-1 1.1 or 1.2b strains, the results revealed that the combined vaccine group prompted a high degree of production of cytokines, B cells, and T cell-associated signaling pathways and was able to elicit considerably greater antibody titers (p < 0.01). Under experimental challenge conditions, the combined vaccine reduced BoAHV-1 viral shedding by 70% in vaccinated cattle compared to controls, and a shorter duration of virus shedding was also observed in the vaccinated groups compared to the non-immune challenge group for different BoAHV-1 strain challenges, about 6-8 days earlier clearance of virus shedding compared to the non-immune challenge group. Notably, the combined vaccine provided cross-protection against multiple BoAHV-1 genotypes, demonstrating its potential as a broad-spectrum solution for controlling bovine respiratory disease. These findings introduce an M. bovis-BoAHV-1 combined vaccine for application in the cattle industry, providing important insights into effective disease control strategies for cattle herds.

The audience take away from presentation:

• Audiences will learn about the development and efficacy of an attenuated and marker M. bovis-BoAHV-1 combined vaccine, which offers dual protection against two major bovine respiratory pathogens. The results support the potential use of this combined vaccine in cattle herds to reduce respiratory disease incidence, shorten virus shedding duration, and decrease pathogen transmission—key benefits for cattle health management.
• The presentation will provide evidence of cross-genotype protection and reduced viral shedding regarding BoAHV-1, offering valuable knowledge for researchers and veterinarians aiming to control diverse BoAHV-1 field strains.
• Audiences will gain an in-depth understanding of the immune responses involved in the series of studies, including enhanced cellular and humoral responses, cytokine and pathological profiles, which offer data support for future vaccine design and evaluation protocols.
• Our series of studies provide valuable insights for veterinary professionals and researchers involved in cattle health management regarding vaccine commercialization, policy development, and integrated disease control programs.