Preclinical study compares intranasal BPI3Vc-vector vaccine to commercial vaccine for calves

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Frontiers in Medicine Published May 19, 2026 Medically reviewed May 19, 2026 Study authors: Huldah Sang, Tae Kim, Rakshith Kumar, Jayden McCall, Aloysius Abraham, Tsvetoslav Koynarski, Michell… DOI ↗ By Dr. Amelia Tan, PhD · Internal Medicine & Chronic Disease

Key Takeaway

Consider the preclinical evidence for a novel intranasal BVDV vaccine in calves, noting it is early and requires further validation.

This is a preclinical study in calves evaluating an intranasal immunization with a cocktail of recombinant BPI3VcmutBVDV viruses compared to a commercial vaccine. The primary focus was the elicitation of strong serum antibodies and virus-neutralizing titers against BVDV-1 and -2 viruses.

The authors report that IgG responses against BVDV-1b CA0401186a were stronger than the commercial vaccine (p=0.0031), as were responses against BVDV-1b TGAC (p=0.0002). Virus-neutralizing titers against several BVDV-2a strains were also significantly higher, including strain 296NC (p=0.0006), strain 890 (p=0.0020), strain 296C (p=0.0464), strain A125 (p=0.0018), and strain 1373 (p=0.0025).

Secondary outcomes upon challenge with BVDV-1b CA0401186a included steady weight gain, less decrease in lymphocyte counts, lower viremia, and fewer gross lesions compared to the commercial vaccine. No effect sizes, absolute numbers, or follow-up durations were reported.

The authors note that this work supports the use of the live-attenuated BPI3Vc-vector for developing contemporary broadly protective BVDV vaccines. Limitations of the preclinical design, such as the lack of reported sample size, setting, or safety data, were not detailed in the source. Practice relevance is restrained to vaccine development support.

Study Details

Study typeGuideline

EvidenceLevel 5

PublishedMay 2026

View Original Abstract ↓

Bovine Viral Diarrhea Virus (BVDV) is a key contributor to the development of Bovine Respiratory Disease complex, which can cause respiratory disease, congenital defects, severe diarrhea, immunosuppression, abortion, or birth of persistently infected calves. Current commercial vaccines are formulated using strains from BVDV-1a and BVDV-2a, conferring protection against some, but not all, homologous species and low neutralization titers against heterologous and emergent species. This study aimed to develop a live vaccine capable of inducing broad protection against diverse BVDV strains. A contemporary live-attenuated BPI3Vc-vectored BVDV prototype vaccine was developed. Novel chimeric BVDV E2-NS2-51–2 antigens, designed based on the consensus of all BVDV-1a, -1b, -2a, -2b, and -2c protein sequences, were used to generate recombinant BPI3VcmutantE2-NS2-51–2 viruses. The recombinant viruses expressed all the ~5kb encoded transgenes, replicated efficiently, remained genetically stable over nine passages in vitro, and displayed the E2 ectodomain on the surface of infected cells. Intranasal immunization of calves with a cocktail of these recombinant viruses, designated rBPI3VcmutBVDV, elicited strong serum antibodies against BVDV-1 and -2 viruses compared to a commercial vaccine. Notably, vaccination elicited stronger IgG responses against BVDV-1b CA0401186a and TGAC, with significantly higher virus-neutralizing titers than the commercial vaccine (CA0401186a: p=0.0031; TGAC: p=0.0002). Immunized calves also elicited significantly higher VN titers against BVDV-2a strains 296NC (p=0.0006), 890 (p=0.0020), 296C (p=0.0464), A125 (p=0.0018), and 1373 (p=0.0025). Upon challenge with BVDV-1b CA0401186a, the rBPI3VcmutBVDV vaccinees exhibited a steady weight gain, less decrease in lymphocyte counts, lower viremia, and fewer gross lesions. This data supports use of the live-attenuated BPI3Vc-vector for development of contemporary broadly protective BVDV vaccines that can easily be upgraded for improved disease management and cattle productivity.