Studies on transplacental transmissibility of a Bovine Virus Diarrhoea (BVD) vaccine virus^1,2

Abstract

Summary Of 84 pregnant cows 15 to 90 days before parturition, 36 had no detectable neutralizing antibodies against BVD virus strain A 1138/69 (group I), while 48 animals exhibited such antibodies (group II). All cows were vaccinated with a commercial BVD live virus vaccine on the day of blood sampling for serological testing as well as for cultural isolation of BVD virus from peripheral blood leucocytes. The latter was unsuccessful in every case. In pre‐colostral blood samples of 31 (86 %) of 36 calves in group I cows neutralizing antibody titres ranged between 1: 80 and 1: 216; of the group II calves 43 (91 %) had no detectable antibodies with only 4 calves having titres between 1: 20 and 1: 180. One cow aborted. The kinetics of neutralizing antibodies were followed up to 12 weeks of life in the calves of both groups. In calves born with pre‐colostral antibodies and vaccinated before ingestion of maternal antibody, the serological response to the vaccine virus did not differ from that of the calves without vaccination, thus indicating that active immunization of the calves in utero most probably occurred following transplacental transmission of the vaccine virus. Calves born without pre‐colostral neutralizing antibodies were immunized actively after pre‐colostral vaccination, while calves which remained unvaccinated showed a decay of maternal antibodies as was to be expected. Death rates of calves in both groups showed no obvious difference. The results are discussed in the light of the diagnostic interpretation in fatal cases of BVD virus infections as well as with respect to the prophylactic value of vaccination. Zusammenfassung Untersuchungen zur transplazentaren Übertragung eines Bovinen Virus Diarrhoe (BVD) Vakzinevirus I. Inokulation tragender Rinder 15 bis 90 Tage vor dem Abkalben (190. bis 265. Trächtigkeitstag) Von 84 Rindern wiesen 15 bis 90 Tage vor dem Abkalben 36 Tiere keine neutralisierenden Antikörper gegen BVD‐Virusstamm A 1138/69 (Gruppe I) auf, während bei 48 Tieren (Gruppe II) solche nachgewiesen werden konnten. Am Tag der Entnahme der Blutproben zur Bestimmung neutralisierender Antikörper gegen BVD‐Virus sowie zur BVD‐Virusisolierung aus peripheren Leukozyten erfolgte die Vakzination aller Kühe mit einer kommerziellen BVD‐Lebendvakzine. Bei keinem der Tiere konnte zuvor eine BVD‐Virämie nachgewiesen werden. In den präkolostralen Seren von 31 (86 %) der insgesamt 36 Kälber in Gruppe I reichten die neutralisierenden Antikörpertiter von 1: 80 bis 1: 216. In Gruppe II besaßen 43 Kälber (91 %) keine präkolostralen neutralisierenden Antikörpertiter, während bei nur vier Kälbern Antikörpertiter zwischen 1: 20 und 1: 80 gefunden wurden. Eine Kuh abortierte. Die Kinetik neutralisierender Antikörper in beiden Kälbergruppen wurde bis zur 12. Lebenswoche verfolgt. Die serologische Antwort der mit präkolostralen Antikörpern geborenen und vor Kolostrumaufnahme vakzinierten Kälber auf die BVD‐Lebendvirus‐vakzine unterschied sich nicht von derjenigen nichtvakzinierter Kälber. Somit hat eine aktive Immunisier...

Seroprevalence of bovine viral diarrhoea virus in Hungary — situation before launching an eradication campaign

“…It is also possible that such farms used a live attenuated vaccine in the past and that this vaccine strain causes antibody generation in subsequent offspring. It is reported that such a strain was widely used in Hungary in the 1990s, resulting in rapid spread of the disease through herds, since it was demonstrated that live vaccine virus can cross the placenta (Orban et al, 1983). Pregnant animals vaccinated during this period were also affected, with those vaccinated in the first half of gestation transmitting the virus to their offspring.…”

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

“…From the results described in the present communication, it appears that similar conditions apply to the BVD live virus vaccine tested. The use of any modified BVD virus calls for critical consideration of vaccination relative to the hazards of live virus vaccines for the fetus (KAHRS, 1972LIES et al, 1983). This finds support in the observation, that in addition to malformations, BVD vaccine virus after transplacental transmission in seronegative dams vaccinated before the 120th day of gestation induces congenital infections.…”

“…Similar to the procedure described in a preceding communication ( ORBAN et al, 1983). all cattle in seven dairy/breeding herds were tested for neutralizing antibodies against BVD virus and two herds were selected where the percentage of seropositive animals was only 52 (herd A) and 36 (herd B), respectively.…”

“…In the seronegative group of animals, 61 were pregnant between 51 and 259 days. They were all vaccinated on the same day with the same batch of BVD live virus vaccine as used in a former trial ( ORBAN et al, 1983). This latter herd was the one where the most impressive results were obtained.…”

“…In the seronegative group of animals, 61 were pregnant between 51 and 259 days. They were all vaccinated on the same day with the same batch of BVD live virus vaccine as used in a former trial ( ORBAN et al, 1983). This latter herd was the one where the most impressive results were obtained.After the initial serological screening with selection of the seronegative cows pregnant at various stages, all these animals were re-tested in order to ensure that they were still seronegative on the day of vaccination.…”