In a significant stride towards combating severe diarrhea in calves, researchers have developed a promising bivalent vaccine that targets two emerging pathogens: bovine norovirus (BNoV) and bovine nebovirus (BNeV). The study, published in *BMC Microbiology*, details the construction and evaluation of a recombinant adenovirus vector vaccine, rAd5-BNoV + BNeV_VP1, which encodes the VP1 proteins of both viruses. This breakthrough could have substantial commercial impacts for the agriculture sector, particularly in reducing economic losses due to calf morbidity and mortality.
The vaccine, based on a replication-deficient human adenovirus type 5 (rAd5), was tested in both mice and calves. Lead author Taoyun Chen from the College of Animal and Veterinary Sciences at Southwest Minzu University explained, “Our goal was to create a vaccine that could induce a robust immune response against both BNoV and BNeV. The results have been very encouraging.”
In mice, the vaccine elicited significant VP1-specific IgG titers as early as two weeks post-vaccination. The antibody response was strong, with BNoV-VP1-specific IgG titers peaking at 1:105 in both intramuscular (I.M.) and oral groups. Similarly, BNeV-VP1-specific IgG titers peaked at 1:105 in the I.M. groups and 1:104 in the oral groups. The serum blocking titer 50 (BT50) values also showed promising results, peaking at 640 in the I.M. groups and 576 in the oral groups. Additionally, the vaccine stimulated a notable increase in IL-4-producing cells and CD3+CD8+ T cells in splenocytes, indicating a robust cellular immune response.
The vaccine’s efficacy was further validated in calves. Following a booster I.M. injection, serum BNoV-VP1-specific and BNeV-VP1-specific IgG antibody titers were significantly higher compared to controls. The BT50 in immunized calves reached 1:80 at 21 and 35 days post-immunization, demonstrating the vaccine’s potential to confer protective immunity.
The implications for the agriculture sector are profound. BNoV and BNeV are responsible for severe diarrhea in calves worldwide, leading to substantial economic losses due to treatment costs, reduced growth rates, and increased mortality. A bivalent vaccine that can effectively target both pathogens could revolutionize calf health management, particularly in regions where these viruses are prevalent.
“This research opens up new avenues for developing vaccines that can protect against multiple pathogens simultaneously,” Chen noted. “The bivalent approach not only simplifies vaccination protocols but also enhances overall immunity, which is crucial for the well-being of calves and the economic viability of livestock operations.”
The study’s findings suggest that rAd5-BNoV + BNeV_VP1 could be a game-changer in the fight against BNoV and BNeV. As the agriculture sector continues to seek innovative solutions to combat infectious diseases in livestock, this research paves the way for future developments in veterinary medicine. The potential for commercialization and widespread adoption of this vaccine could significantly improve calf health and reduce the financial burden on farmers.
The research, led by Taoyun Chen from the College of Animal and Veterinary Sciences at Southwest Minzu University, was published in *BMC Microbiology*, highlighting the importance of interdisciplinary collaboration in addressing global agricultural challenges.