Safety testing of veterinary vaccines using magnetic resonance imaging in pigs

Safety testing of veterinary vaccines requires the use of a large number of animals to investigate possible local and systemic reactions. This includes, among others, the pathological examination of the injection site in frequent intervals. This examination requires a selected killing of animals in frequent intervals. To reduce the number of animals needed for this kind of safety testing, magnetic resonance imaging (MRI) was used to detect and quantify possible local reactions after vaccination in vivo. Sixty-four pigs were divided into four experimental groups (n = 16);two groups consisting of 12-week-old pigs and two of 6-month-old pigs at vaccination day. The pigs were vaccinated with four licensed products (each group receiving one vaccine) and examined up to 6 times using MRI during a period of 5 weeks. The MR images were evaluated semi-automatically, comparing the volumes of altered signal intensities on the vaccination side (VS) with the volumes of the signal intensities on the control side (CS). A paired t-test was used to identify significant differences (p < 0.05) between VS and CS. The results show that MRI allows a 3D-quantification of the extent of local reactions in vivo by scanning the same live animals at several time points after vaccination. MRI is a suitable alternative method for non-invasive safety testing of injectable medicines and can therefore be applied to reduce animal numbers used for safety testing purposes

Assessment of Local Reaction to Vaccines in Live Piglets with Magnetic Resonance Imaging Compared to Histopathology

The safety of veterinary vaccines is assessed in clinical trials in Europe. The assessment of the local tissue reaction to vaccination by magnetic resonance imaging (MRI) could reduce the number of animals needed because repeated examinations can be performed in the same animal over time. The present study compared the evaluation of local tissue reactions to vaccination using MRI in live pigs with histopathology of porcine tissue, the current gold standard in regulatory safety testing. Eight piglets each were administered one of two commercial vaccines into marked injection sites. All animals were sedated and scanned repeatedly by MRI using a contrast agent up to day 29 after vaccination. On day 29, the animals were euthanized and underwent a pathological examination. The MRI results were compared with the pathomorphological findings at the injection site by regression analysis. The MR images and the pathological examinations yielded matching results concerning the sizes of the affected tissue volumes or areas. The use of MRI for regulatory safety testing can reduce the number of animals needed to 8 per examination group. The volume of a local reaction and its progression over time can be evaluated and documented. If persistent lesions develop a final pathomorphological examination is needed to identify the kind and local distribution of the reaction

Bovine Neonatal Pancytopenia-Associated Alloantibodies Recognize Individual Bovine Leukocyte Antigen 1 Alleles

Bovine neonatal pancytopenia (BNP) was a vaccine-induced alloimmune disease observed in young calves and characterized by hemorrhages, pancytopenia, and severe destruction of the hematopoietic tissues. BNP was induced by alloreactive maternal antibodies present in the colostrum of certain cows vaccinated with a highly adjuvanted vaccine against bovine viral diarrhea. Bioprocess impurities, originating from the production cell line of the vaccine, are likely to have induced these alloreactive antibodies. One prominent alloantigen recognized by vaccine-induced alloantibodies is highly polymorphic bovine major histocompatibility complex class I antigen (bovine leukocyte antigen 1—BoLA I). Aim of this study was to define the fine specificity of BNP-associated anti-BoLA I alloantibodies. In total, eight different BoLA I alleles from the production cell line were identified. All genes were cloned and recombinantly expressed in murine cell lines. Using these cells in a flow cytometric assay, the presence of BoLA I specific alloantibodies in BNP dam sera was proven. Three BoLA I variants were identified that accounted for the majority of vaccine-induced BoLA I reactivity. By comparing the sequence of immunogenic to non-immunogenic BoLA I variants probable minimal epitopes on BoLA I were identified. In general, dams of BNP calves displayed high levels of BoLA I reactive alloantibodies, while vaccinated cows delivering healthy calves had significantly lower alloantibody titers. We identified a subgroup of vaccinated cows with healthy calves displaying very high alloantibody titers. Between these cows and BNP dams no principle difference in the BoLA I reactivity pattern was observed. However, with a limited set of dam-calf pairs it could be demonstrated that serum from these cows did not bind to BoLA I expressing leukocytes of their offspring. By contrast, when testing cells from surviving BNP calves with the corresponding dam’s serum there was significant binding. We therefore conclude that predominantly highly alloreactive cows are at risk to induce BNP and it depends on the paternally inherited BoLA I whether or not the calf develops BNP

Future Activities: ECVAM and the Quality Control of Biologicals.

Abstract not availableJRC.I-Institute for Health and Consumer Protection (Ispra

Incidence of bovine neonatal pancytopenia in 243 farms in Germany

Background: Several research groups from different European countries have worked on the aetiopathogenesis of bovine neonatal pancytopenia (BNP) and an association between the use of the vaccine PregSure BVD (Pfizer, Germany) and the development of this haemorrhagic disease was confirmed. Because BNP is not a notifiable disease, it is difficult to obtain information on its incidence. Based on pharmacovigilance (PhV) data, which are the only officially available data at the national level, the incidence of BNP is considered low. However, voluntary reporting of the disease can lead to underreporting. To gain more insight into the incidence of BNP among the affected herds, an epidemiological study was performed, which focused on 243 farms in Germany with cases of BNP. Farmers were asked to report the occurrence of BNP, including the number of cases, which allowed calculation of incidence in the affected herds. Matching such data with the registered cases in the National PhV System (NPhVS) gave us an opportunity to assess the extent of BNP underreporting. Results: On 243 farms, a total of 1195 calves younger than 4 weeks with haemorrhagic diathesis were registered. In 58 % of the reports, a diagnosis of BNP was confirmed by blood analysis and or by necropsy. The number of cases observed on individual farms ranged from 1 to 80. Based on these results, the incidence of BNP on affected farms ranged from 0.3 to 15.2 % (median 2.9 %). The maximal incidence in the year with the highest number of BNP calves ranged between 0.4 and 18.6 % (median 3.3 %). Comparing the number of cases registered in the NPhVS to the numbers found in this study revealed considerable underreporting to the national database: only 44 % of the farms and 41 % of the BNP calves included in the study were registered in the NPhVS. Conclusions: In spite of the opportunity to report BNP calves to the Paul-Ehrlich-Institut (Langen, Germany), the estimated number of undetected BNP cases is remarkably high. However, even if the revealed substantial underreporting is taken into account, the incidence of BNP is low. Nevertheless, the incidence on some affected farms is very high, resulting in considerable financial losses that should not be underestimated. Although the exact pathomechanism of BNP at the molecular level is still not known, its incidence is clearly declining following withdrawal of PregSure BVD from the market

ECVAM's Activities on Biologicals.

Abstract not availableJRC.I-Institute for Health and Consumer Protection (Ispra

ECVAM's Activities on Promoting the Three Rs in the Quality Control of Biologicals.

Abstract not availableJRC.I-Institute for Health and Consumer Protection (Ispra

ECVAM's Contributions to the Implementation of the Three Rs in the Production and Quality Control of Biologicals.

Abstract not availableJRC.I-Institute for Health and Consumer Protection (Ispra

Verdacht auf Übertragung von Q-Fieber durch Frischzellentherapie

In Deutschland werden seit 1931 Frischzellenzubereitungen nach Paul Niehans als Arzneimittel zur Behandlung von Alters- und Verschleißerkrankungen („Anti-Aging“) sowie Gesundheitsstörungen unterschiedlicher Art eingesetzt. Die Frischzellen werden aus homogenisierten Organen und Geweben von Schafsfeten und Schafen gewonnen und als Zellsuspensionen aufbereitet. Innerhalb von zwei Stunden nach der Gewinnung und Herstellung werden die gepufferten Zellsuspensionen intragluteal injiziert

Live Cell Therapy as Potential Risk Factor for Q Fever

During an outbreak of Q fever in Germany, we identified an infected sheep flock from which animals were routinely used as a source for life cell therapy (LCT), the injection of fetal cells or cell extracts from sheep into humans. Q fever developed in 7 LCT recipients from Canada, Germany, and the United States