Conference Proceeding

Determination of protection provided by two modified live bovine herpesvirus-1 vaccines against bovine herpesvirus-1 conjunctivitis in calves

Walz, Paul H, Short, Thomas H, Scruggs, Daniel, Cortese, Victor S

2023

Overview

BoHV-1 can be differentiated on the DNA level into 3 subtypes by restriction endonuclease methods.3,4,6,10 BoHV-1 causes a variety of clinical signs, e.g., rhinotracheitis, fever, conjunctivitis, drop in milk production, abortion, reproductive losses, encephalitis and lesions of the mucous membranes of the genital tract.6,8,11,12 While many studies have been published on the respiratory and reproductive forms of BoHV-1, little has been published on the impact of BoHV-1 on the bovine eye. Phase II of the study was designed to assess protection afforded by 2 separate modified live BoHV-1 vaccines in the challenge model described in Phase I. Phase I All study procedures were approved by the Auburn University Animal Care and Use Committee (IACUC, PRN 2020-3792). Each steer was individually identified using a unique numbered ear tag. Since phase I of this study was designed to see if conjunctivitis could be caused by the virus and spread among calves, no power calculation was necessary. The culture/PCR results from study 1 showed 100% infected eyes. Since no previous study was found to determine vaccine efficacy against BoHV-1 induced conjunctivitis, a decrease in infection of 50% was used in sample size determination using an alpha = 0.10 and 80% power.

• Publisher: American Phytopathological Society
• Subject: Beef / Cattle / Cell culture / Conjunctivitis / Encephalitis / Endonuclease / Genital tract / Herpes viruses / Immunization / Milk production / Vaccine efficacy / Vaccines