Fulton Robert W, Cook Billy J, Payton Mark E, Burge Lurinda J, Step D L
Department of Veterinary Pathobiology, Oklahoma State University, Stillwater, OK 74078, USA.
Noble Research Institute, Ardmore, OK 73401, USA.
Vaccine. 2020 May 19;38(24):4032-4037. doi: 10.1016/j.vaccine.2020.03.058. Epub 2020 Apr 24.
Bovine viral diarrhea virus (BVDV) represents a major cattle disease with multiple forms including fetal infections resulting in persistently infected (PI) cattle. The objectives of this study were to investigate the immune response to six vaccines, five modified live viral (MLV) and one killed vaccine containing BVDV immunogens as measured by antibodies to BVDV1a, BVDV1b, BVDV2a, and BVDV2c. The predominant BVDV subgenotype in the U.S. is BVDV1b compared to BVDV1a and BVDV2a. There are MLV and killed BVDV vaccines containing BVDV1a and BVDV2a marketed in the U.S. A prior study evaluated immune response to vaccination with BVDV1a and BVDV2a inducing virus neutralizing antibody titers. BVDV1b titers 128 or higher at time of exposure to BVDV1b PI cattle protected heifers against fetal infection. Calves received two doses and postweaning serums were collected and assayed for BVDV antibodies. Antibody titers were expressed as geometric mean averages. Percentages were expressed as proportions of animals within three antibody levels, including targeted level 128 or greater. There were statistical differences among vaccines in each study, particularly to BVDV1a, BVDV1b, and BVDV2a. MLV vaccines containing Singer strain induced higher levels to BVDV1a and BVDV1b than NADL vaccine in all three studies. Two vaccines, both MLV, Vaccine 1 and Vaccine 6 containing Singer strain induced higher proportion of 128 or higher BVDV1b titers than vaccine with NADL. Antibody levels to BVDV2a and BVDV2c were dependent on BVDV2a vaccine strain. This study indicates strain in BVDV vaccines reflects differences in immune response to different BVDV subgenotypes, particularly BVDV1b and BVDV2c.
牛病毒性腹泻病毒（BVDV）是一种主要的牛病，有多种形式，包括导致持续感染（PI）牛的胎儿感染。本研究的目的是通过检测针对BVDV1a、BVDV1b、BVDV2a和BVDV2c的抗体，来研究对六种疫苗（五种改良活病毒（MLV）疫苗和一种含有BVDV免疫原的灭活疫苗）的免疫反应。与BVDV1a和BVDV2a相比，美国主要的BVDV亚基因型是BVDV1b。美国市场上有含BVDV1a和BVDV2a的MLV和灭活BVDV疫苗。先前的一项研究评估了接种BVDV1a和BVDV2a诱导病毒中和抗体滴度后的免疫反应。接触BVDV1b PI牛时，BVDV1b滴度为128或更高可保护小母牛免受胎儿感染。犊牛接种两剂疫苗，断奶后采集血清并检测BVDV抗体。抗体滴度以几何平均平均值表示。百分比表示为处于三个抗体水平（包括目标水平128或更高）的动物比例。每项研究中不同疫苗之间存在统计学差异，特别是针对BVDV1a、BVDV1b和BVDV2a。在所有三项研究中，含辛格毒株的MLV疫苗诱导的BVDV1a和BVDV1b水平高于NADL疫苗。两种MLV疫苗，即疫苗1和含辛格毒株的疫苗6，诱导出128或更高BVDV1b滴度的比例高于含NADL的疫苗。对BVDV2a和BVDV2c的抗体水平取决于BVDV2a疫苗毒株。本研究表明，BVDV疫苗中的毒株反映了对不同BVDV亚基因型，特别是BVDV1b和BVDV2c免疫反应的差异。
