Studies on transplacental transmissibility of a Bovine Virus Diarrhoea (BVD) vaccine virus in cattle¹

Abstract

Summary In two cattle herds pregnant cows and heifers negative to BVD virus infection by neutralization tests were vaccinated with a commercial live virus vaccine at various stages of gestation (51 to 259 days). Of 23 calves born alive after their dams had been vaccinated between day 123 and 259 of pregnancy, none were viraemic when buffy coat was tested for BVD virus, but all pre‐colostral blood samples collected from 14 calves contained neutralizing antibodies to BVD virus. Of 21 cows vaccinated between the 118th and 51st day of pregnancy, 13 animals delivered apparently healthy calves (group I) while the others showed more or less severe clinical symptoms, with or without perinatal death (group II). Among the group I animals, 9 were shown to be viraemic and BVD virus persistence could be followed up in some cases up to 2 years of age. In group II, 5 calves derived from dams vaccinated between the 90th and 113th day of pregnancy, showed central nervous symptoms with torticollis, ataxia or astasia. From one animal BVD virus was isolated from the cerebrospinal fluid but not from blood or organs. Three other calves in group II died perinatally. The results are discussed in view of the demonstration of viral persistence and teratogenic effects induced by vaccine virus being detectable for some considerable time — at the delivery of the calf at full term or even for a long time thereafter. It is advised that a modified BVD live virus vaccine not tested for possible transplacental transfer should not be used in pregnant cattle. The use of such vaccines should be restricted to an age prior to breeding and when no interference between colostrally transferred maternal antibodies and the vaccine is to be expected. Zusammenfassung Untersuchungen zur transplazentaren Übertragung eines “Bovine Virusdiarrhoe (BVD)”‐Vakzinevirus II. Inokulation tragender Rinder 90–229 Tage vor dem Abkalben (51. bis 190. Trächtigkeistag) In zwei Rinderherden wurden tragende Kühe und Färsen, die keine neutralisierenden Antikörper gegen BVD‐Virus aufwiesen, mit einer kommerziellen Lebendvirus‐Vakzine in verschiedenen Trächtigkeitsstadien geimpft (51–259 Tage). Unter 23 lebendgeborenen Kälbern, deren Mütter zwischen dem 123. und 259. Tag vakziniert worden waren, fand sich keins mit Virämie, als Leukozytenfraktionen des peripheren Blutes (“buffy coats”) entsprechend untersucht wurden. Alle präkolostral gewonnenen Blutproben von 14 der 23 Kälber wiesen neutralisierende Antikörper gegen BVD‐Virus auf. Von 21 Kühen, die zwischen dem 118. und 51. Trächtigkeitstag vakziniert worden waren, wurden 13 gesund erscheinende Kälber (Gruppe I) geboren, während die restlichen mehr oder weniger schwere klinische Symptome aufwiesen und teilweise perinatal starben (Gruppe II). Unter den 13 Kälbern in Gruppe I fanden sich 9 mit BVD‐Virämie; BVD‐Viruspersistenz konnte in einigen Fällen bis zum Alter von zwei Jahren verfolgt werden. In Gruppe II befanden sich 5 Kälber von Müttern, die zwischen dem 90. und 113. Trächtigkeitstag vakziniert worden waren. Diese Kälber ze...

Immunohistological detection of bovine viral diarrhoea virus antigen in the central nervous system of persistently infected cattle using monoclonal antibodies

“…Persistent infection with bovine viral diarrhoea virus (BVDV) may occur if the bovine fetus is transplacentally infected with non-cytopathic BVDV at a time when it is still immunologically immature ( Coria and McClurkin, 1978;Liess et al, 1984;McClurkin et al, 1984;Roeder et al, 1986). Fetal infection during the first 4 months of gestation results in immunological tolerance to the homologous virus.…”

Bovine Viral Diarrhea Virus in Cattle From Mexico: Current Status

“…In most cases, the purpose of vaccination is to prevent reproductive failure, gastrointestinal disorders, and respiratory disease; therefore, it is common to include BVDV1 and sometimes BVDV2 in multi-component vaccines, i.e., vaccines against BRDC. When applied improperly, unwanted effects need to be considered and evaluated; i.e., the use of MLV's of CP strains during pregnancy had led to reproductive disorders, recombination with field strains, and development of mucosal disease in PI animals (39)(40)(41). These events are rarely identified and reported in the Mexican cattle industry.…”