Bovine Viral Diarrhea Virus Type Research Articles

Complete Genome Sequence of Bovine Viral Diarrhea Virus Subgenotype 2a Strain CN10.2015.821, Isolated in Piedmont, Italy.

ABSTRACTWe sequenced the complete genome of noncytopathic bovine viral diarrhea virus (BVDV) type 2 strain CN10.2015.821. It belongs to the subgenotype 2a, and it was isolated from an immunotolerant and persistently infected calf identified during a serological investigation. The complete genome is composed of 12,273 nucleotides, organized as one open reading frame encoding 3,897 amino acids.

Detection and genetic identification of pestiviruses in Brazilian lots of fetal bovine serum collected from 2006 to 2014

ABSTRACT: The present study performed a genetic identification of pestiviruses contaminating batches of fetal bovine serum (FBS) produced in Brazil from 2006 to 2014. Seventy-three FBS lots were screened by a RT-PCR targeting the 5’untranslated region (UTR) of the pestivirus genome. Thirty-nine lots (53.4%) were positive for pestivirus RNA and one contained infectious virus. Nucleotide sequencing and phylogenetic analysis of the 5’UTR revealed 34 lots (46.6%) containing RNA of bovine viral diarrhea virus type 1 (BVDV-1), being 23 BVDV-1a (5’ UTR identity 90.8-98.7%), eight BVDV-1b (93.9-96.7%) and three BVDV-1d (96.2- 97.6%). Six lots (8.2%) contained BVDV-2 (90.3-100% UTR identity) being two BVDV-2a; three BVDV-2b and one undetermined. Four FBS batches (5.5%) were found contaminated with HoBi-like virus (98.3 to 100%). Five batches (6.8%) contained more than one pestivirus. The high frequency of contamination of FBS with pestivirus RNA reinforce the need for systematic and updated guidelines for monitoring this product to reduce the risk of contamination of biologicals and introduction of contaminating agents into free areas.

Establishment of a Bovine Viral Diarrhea Virus Type 2 Intranasal Challenge Model for Assessing Vaccine Efficacy.

The objective of this study was to develop a bovine viral diarrhea virus type 2 (BVDV-2) challenge model suitable for evaluation of efficacy of BVDV vaccines; a model that mimics natural infection and induces clear leukopenia and viremia. Clinical, hematological and virological parameters were evaluated after infection of two age groups of calves (3 and 9 months) with two BVDV-2 strains (1362727 and 502643). Calves became pyrexic between 8 and 9 days post inoculation and exhibited symptoms, such as nasal discharge, mild depression, cough, and inappetence. Leukopenia with associated lymphopenia and neutropenia was evident in all groups with lowest leukocyte and lymphocyte counts reached 8 dpi and granulocyte counts between 11 and 16 dpi, dependent on the strain and age of the calves. A more severe thrombocytopenia was seen in those animals inoculated with strain 1362727. Leukocyte and nasal swab samples were positive by virus isolation, as early as 3 dpi and 2 dpi respectively, independent of the inocula used. All calves seroconverted with high levels of BVDV-2 neutralizing antibodies. BVDV RNA was evident as late as 90 dpi and provides the first evidence of the presence of replicating virus long after recovery from BVDV-2 experimental infection. In summary, moderate disease can be induced after experimental infection of calves with a low titer of virulent BVDV-2, with leukopenia, thrombocytopenia, viremia, and virus shedding. These strains represent an attractive model to assess the protective efficacy of existing and new vaccines against BVDV-2.

Bovine viral diarrhea virus type 1 current taxonomy according to palindromic nucleotide substitutions method

Pestivirus bovine viral diarrhea virus type 1 species is responsible for cosmopolitan diseases affecting cattle and other ruminants, presenting a wide range of clinical manifestations, with relevant impact on zootechnic production. Understanding genomic characteristic and virus taxonomy is fundamental in order to sustain control and prophylactic programs. Given the recent various studies reporting a relatively high number of new strains, in particular from Asian countries, in the present study, four hundred-eighty-two genomic sequences have been evaluated applying the palindromic nucleotide substitutions method for genotyping. Based on the secondary structure alignment and computing genetic distance among strains in the 5′ untranslated region of Pestivirus RNA, the current taxonomy of the species was reviewed. Twenty-two genotypes have been identified, applying a nomenclature based on divergence in the genus.

Identification of Bovine Viral Diarrhoea Virus Type 2 in Cattle Bull Semen from Southern India and its Genetic Characterization

Although bovine viral diarrhoea virus (BVDV) is prevalent in Indian cattle causing economic losses in cattle farming, its detection in bull semen has not yet been reported. Following passage of raw bull semen (n = 4) on MDBK cells, testing for BVDV was done by antigen ELISA and real-time RT-PCR. BVDV type-2 (BVDV-2) was identified in three samples from southern India by real-time RT-PCR. Genetic typing of the 5'-UTR sequences classified all the three BVDV strains as BVDV-2a subtype. These were found genetically closely related to the strains from USA, but divergent from the BVDV-2a strains from northern India. Phylogenetic analysis of N pro sequences confirmed the findings. The results provide evidence of circulation of BVDV-2a strains in southern India. The detection of BVDV in bull semen from India highlights the importance of mandatory testing of breeding bulls and bull semen for BVDV to minimize the risk of BVDV transmission.

Seroprevalence of Bovine Adenovirus and Enterovirus Antibodies Reveals Different Infection Dynamics in Cattle Herds

Background: Bovine enterovirus (BEV) and bovine adenovirus (BAV) are widely distributed in cattle population, and are among possible causes of gastroenteritis and respiratory disease, respectively, although the infection is more often subclinical. BAV infection may be also related to conjunctivitis, and may lead to severe infections and death in immunosuppressive calves. BEV infections have been associated with disorders of respiratory and reproductive tracts, and diarrhea. There is little available information about BAV and BEV in Brazil; however the main of the present study was to investigate the presence of antibodies against these viruses in cattle from some counties of the Rio Grande do Sul (RS), Brazil.Material, Methods & Results: A total of 415 bovine serum samples collected in 2015 year to detect neutralizing antibodies against BEV and BAV by Virus neutralization (VN) assay were performed. The serum samples were gently provided from Setor de Virologia da Universidade Federal de Santa Maria (SV-UFSM). The samples came from bovine with a history or report of clinical cases of diarrhea, respiratory and reproducible disorders and/or abortion suggestive of Leucosis, Bovine Viral Diarrhea Virus (BVDV) and/or Bovine herpesvirus type 1 and 5 (BoHV-1 and 5) infections. The samples are originated as from dairy and beef herd cattle in the following regions from RS State: Southwest, Northeast, Northwest, West, Southeast, Midwest and Metropolitan regions; and were classified according to the origin, gender and age. The serum samples were tested against 100 TCID50/mL of (tissue cellular infection dose 50/mL) of previously characterized BEV and BAV-3 isolates. Serial dilution of the serum was performed in duplicate, starting at 1:5 up to > 1:640 for BEV and at 1:2 to > 1:256 for BAV in 96 wells plates. The serum and virus mixture was incubated in 37ºC for 4-6 h and then a suspension of CRIB cells was added to each well. The plates were incubated in 37ºC and 5% CO2 for three days for BEV and five days for BAV assay. Neutralization titers were calculated as the reciprocal of the highest serum dilution able to avoid the cytopathic effect. A total of 99.7% (414/415) serum samples showed neutralizing antibodies to BAV and/or BEV. 99.2% (411/414) showed neutralizing antibodies against only BEV and 97.3 % (403/414) were seropositive only to BAV3. Regarding the sex of the analyzed population, males corresponded to 41.6% (173/415) and female 30.3% (126/415) of the total. From BEV seropositive samples, a higher frequency of neutralizing antibodies titers of 1:320, regarding 22.1% (91/411) of samples and for BAV-3 the titers > 1:256 were more prevalent, 72.2% (291/403) of seropositive.Discussion: The data in the present study showed that the frequency of neutralizing antibodies was high for both viruses as well as co-infection was prevalent; demonstrated that both viruses are actively circulating in the bovine population. However reinfections with BEV may be related to a higher proportion of animals presenting strong humoral immunity. Since BAV and BEV are normally related to subclinical infections, in the absence of clinical cases and high levels of herd immunity, it could be inferred that no other preventive measures need to be taken in these herds until no clear overt of clinical signs is noticed. In another hand, is important research these viruses in animals with signs historic of respiratory tract disease, reproductive disorders and diarrhea.

Feed Intake and Weight Changes in Bos indicus-Bos taurus Crossbred Steers Following Bovine Viral Diarrhea Virus Type 1b Challenge Under Production Conditions.

Bovine viral diarrhea virus (BVDV) has major impacts on beef cattle production worldwide, but the understanding of host animal genetic influence on illness is limited. This study evaluated rectal temperature, weight change and feed intake in Bos indicus crossbred steers (n = 366) that were challenged with BVDV Type 1b, and where family lines were stratified across three vaccine treatments of modified live (MLV), killed, (KV) or no vaccine (NON). Pyrexia classification based on 40.0 °C threshold following challenge and vaccine treatment were investigated for potential interactions with sire for weight change and feed intake following challenge. Pyrexia classification affected daily feed intake (ADFI, p = 0.05), and interacted with day (p < 0.001) for ADFI. Although low incidence of clinical signs was observed, there were marked reductions in average daily gain (ADG) and cumulative feed intake during the first 14 day post-challenge; ADG (CV of 104%) and feed efficiency were highly variable in the 14-day period immediately post-challenge as compared to the subsequent 14-day periods. A sire × vaccine strategy interaction affected ADFI (p < 0.001), and a sire by time period interaction affected ADG (p = 0.03) and total feed intake (p = 0.03). This study demonstrates that different coping responses may exist across genetic lines to the same pathogen, and that subclinical BVDV infection has a measurable impact on cattle production measures.

Impact of exercise on productivity, behavior, and immune functioning of weaned Bos indicus-cross calves housed in drylots.

The effects of 2 exercise regimes on cattle productivity, immune function, and behavior were evaluated against a control ( = 4 pens/treatment) using weaned -cross calves ( = 203) housed in drylots (16-18 calves/single sex pens). Three treatments were applied 3 times per week for 4 wk: 1) programmatic exercise (PRO), in which cattle and a stockperson walked in the alleyway behind their home pen for 20 min; 2) free exercise (FREE), in which cattle were moved into the drovers alley for 60 min, not exercised by a stockperson, and were allowed free access to their home pen and alleyway; and 3) control (CON), in which calves were removed from their home pen only for routine husbandry. Behavior observations were conducted on d -2 and -1 relative to treatment implementation (d 0) and on d 5, 6, 12, 13, 19, 20, 26, and 27. Instantaneous scan sampling was used to create behavioral profiles for cattle (posture: stand, lie, and walk; and behavior: feed, drink, and ruminate). Focal observations recorded the incidence of social behaviors (allogrooming, social play, and agonistic interactions) and animal-environment interactions (AEI; fencepost licking, rock eating, tongue rolling, and cross-suckling). Body weights, exit velocities, and antibody titers to a bovine viral diarrhea virus type 1b vaccine were measured on d -10, 10, and 28. A linear mixed model (PROC MIXED) was used to evaluate the impact of exercise treatment, sex, time, and their interactions on cattle behavior, health, and productivity. Statistical differences were not observed ( = 0.11) for overall ADG among cattle receiving FREE (1.00 kg ± 0.04) PRO (0.85 kg ± 0.04), or CON (0.86 kg ± 0.05) exercise treatments. Allogrooming ( = 0.05), lying ( < 0. 01), AEI ( < 0.01), rumination ( < 0.01), and agonistic interactions ( < 0.01) increased over time. Comfort-related behaviors (e.g., lying, rumination) increased over the evaluation period, suggesting that calves became acclimated to the environment. Exercise did not alter behaviors or vaccine response and did not reduce the performance of production-critical (e.g., feeding, resting, ruminating) behaviors.

Pestivirus infection in cattle dairy farms: E2 glycoprotein ELISA reveals the presence of bovine viral diarrhea virus type 2 in northwestern Italy

BackgroundBovine viral diarrhea virus (BVDV) types 1 and 2 are members of the Pestivirus genus of the Flaviviridae family. This genus also includes the HoBi-like virus, tentatively classified as BVDV type 3. BVDV-1 is widely distributed in Italy despite the extensive use of BVDV-1-based vaccines, while BVDV-2 and HoBi-like Pestivirus have been detected occasionally. Monitoring the occurrence of sporadic or atypical pestiviruses is a useful approach to evaluate the need for additional vaccine strains that can be used in BVDV control programs.ResultsIn this study we developed a multiwell antibody ELISA based on the recombinant E2 protein of the three bovine pestiviruses. We evaluated the assay’s applicability for surveillance purposes using pooled milk samples, each prepared from a maximum of 35 lactating cows and collected from 176 dairy herds. As expected, the majority of the pooled samples reacted to a greater extent against the BVDV-1 E2 antigen. All three milk pools from a single farm reacted to the BVDV-2 antigen, however. Further analysis using spot tests, antigen detection, and sequence analysis of the 5′-UTR region confirmed the presence of five persistently infected calves carrying a BVDV-2a strain.ConclusionsThis study highlights for the first time that sporadic circulation of BVDV-2 can be predicted by immunoenzymatic methods in the absence of specific vaccination.

Efficacy of bovine viral diarrhea modified-live virus vaccine to provide fetal protection for BVDV type 1 and 2 virus in cattle

Effective control of bovine viral diarrhea virus (BVDV) requires that vaccination provide a high level of protection not only to the dam, but also to the calf in utero, preventing fetal infection and the development of persistently infected (PI) calves. The objective of this study was to determine if primiparous cows vaccinated with a BVDV modified-live virus vaccine (Titanium® 5 L5 HB, Elanco Animal Health, Greenfield, IN, USA) were protected from fetal infections and the development of PI calves following exposure to virulent non-cytopathic type 1 and 2 BVDV.

Npro His49 and Erns Lys412 mutations in pig bovine viral diarrhea virus type 2 synergistically enhance the cellular antiviral response.

Type I interferons are major components of the innate immune response of hosts, and accordingly, many viruses have evolved mechanisms to modulate the host response during infection. Bovine viral diarrhea virus (BVDV) nonstructural protein Npro and structural protein Erns play important roles in inhibiting type I interferon. The aim of this study was to explore the epistatic effects of amino acid mutations in Npro and Erns in porcine ST cells to characterize the immune response induced by BVDV-2. Plasmids with mutant amino acids His49 (H49), Glu22 (E22) in Npro, and His300 (H300), Lys412 (K412) in Erns which had been changed to Alanine (A) had similar effects on type I interferon production in MDBK and ST cells, but resulted in much greater ISG15, OAS, and Mx production in ST cells. The rescued vASH/NproH49ErnsK412 virus showed the best efficiency with respect to modulating antiviral cytokines, indicating that the amino acids Npro H49 and Erns K412 had highly synergistic effects in abolishing the ability to inhibit type I interferon. These findings have importance practical implications owing to the increasing prevalence of BVDV infections, including persistent infections, in domestic pigs.

Analysis of bovine viral diarrhoea virus: Biobank and sequence database to support eradication in Scotland

Samples from bovine viral diarrhoea virus (BVDV)—positive cattle were gathered by Scottish diagnostic laboratories and used to produce a Biobank of samples with associated location and identification data in support...

Comparison of humoral and T-cell-mediated immune responses to a single dose of Bovela® live double deleted BVDV vaccine or to a field BVDV strain

The objective of this study was to determine and compare the humoral and cellular immune responses of calves exposed to a single dose of Bovela® bovine viral diarrhea virus (BVDV) live double deleted vaccine or a field strain virus (FSV) of BVDV type 2 (strain 890). Thirty seronegative, colostrum-deprived 5 month-old Holstein steer calves that tested negative for persistent BVDV by ear notch immunohistochemistry and seronegative to BVDV types 1 and 2 were used. Calves were screened by multi-parameter flow cytometry (MP-FCM) 1 week before vaccination to ensure that they were negative for T cell responses to the BVDV types 1 and 2 viruses in the Bovela® vaccine. Calves were assigned to 3 treatment groups: control (PBS), FSV inoculated, and Bovela® vaccinated. The humoral response was tested by standard serum virus neutralization (SVN) test to BVDV types 1 (Singer strain) and 2 (strain 125). The response by CD4, CD8, and gamma delta (γδ TCR) T cells was evaluated by MP-FCM using individual BVDV types 1 and 2 from Bovela® vaccine as recall antigens at 5, 6, and 7 weeks after vaccination. Activation markers used were upregulation of surface CD25 (IL-2R), intracellular interferon gamma (IFNγ) and intracellular interleukin 4 (IL-4). Each T cell subset was evaluated for increased expression of each activation marker compared to non-antigen stimulated cells of the same animal. All Bovela® vaccinated and FSV inoculated calves produced SVN antibodies to both BVDV types 1 and 2 while control animals remained seronegative throughout the study. The mean (weeks 5, 6, and 7) T cell recall responses to Bovela® BVDV type 1 and type 2 recall antigens were numerically higher in all three T cell subsets (CD4, CD8, and γδ TCR) for all three activation markers (CD25, IFNγ, and IL-4) when compared to either the control animals or to the FSV inoculated animals. These differences were often, but not always, statistically significant (P<0.05)

Prevention of fetal infection in heifers challenged with bovine viral diarrhoea virus type 1a by vaccination with a type 1c or type 1a vaccine

AIMS: To evaluate a vaccine containing type 1c bovine viral diarrhoea (BVD) virus for prevention of fetal infection in pregnant heifers when challenged with New Zealand BVD virus type 1a 6 months after vaccination, compared to unvaccinated heifers and heifers vaccinated with a vaccine containing type 1a BVD virus.METHODS: Fifty five crossbred Friesian heifers, free from BVD virus and antibody, were randomly allocated to three groups. Twenty five heifers were vaccinated twice with a vaccine containing type 1c BVD virus (T1c group), and 10 heifers with a vaccine containing type 1a BVD virus (T1a group), and 20 heifers were unvaccinated (NC group). After oestrus synchronisation the heifers were bred by artificial insemination followed by natural bull mating. Six months after booster vaccination 15 heifers from the T1c group, eight from the T1a group, and 15 from the NC group, were exposed to four calves that were persistently infected with type 1a BVD virus, for 4 weeks. At the beginning of the challenge phase 36/38 heifers were 72–74 days pregnant and 2/38 heifers were approximately 53 days pregnant. Approximately 52 days after the start of the challenge the heifers were subjected to euthanasia and fetal tissues were collected for the detection of BVD virus by ELISA in fetal heart blood and PCR in fetal tissues.RESULTS: Based on PCR results, BVD virus was detected in 15/15 fetuses in the NC group, compared to 4/14 fetuses in the T1c group and 3/8 fetuses in the T1a group. The proportion of BVD virus-positive fetuses was lower in both vaccinated groups compared to the NC group (p<0.002), but there was no difference in proportions between the vaccinated groups (p=1.00). Fetal protection, expressed as the prevented fraction, was 71.4 (95% CI=41.9–91.6)% and 62.5 (95% CI=24.5–91.5)% for the T1c and T1a groups, respectively.CONCLUSIONS AND CLINICAL RELEVANCE: The vaccines containing killed type 1c and type 1a BVD viruses significantly reduced fetal infection following challenge with a New Zealand type 1a BVD virus. Prevention of fetal infection by vaccination may not be 100%, and the risk of persistently infected calves being born to some vaccinated cattle should be acknowledged and managed as part of a BVD control programme.

Systemic granulomatous and haemorrhagic syndrome in New Zealand dairy cattle

CASE HISTORY: Cases were obtained through passive surveillance reporting by veterinary pathologists, via the Ministry for Primary Industries Exotic Pest and Disease Hotline. They included ill or dead cows that had evidence of frank haemorrhage, petechial haemorrhages on mucous membranes, wasting or dermatitis of unknown cause, and were reported between 2009–2014. Affected cows (n=16) were from nine seasonally calving dairy farms, aged ≥3 years, and were predominantly in their mid-to-late non-lactating period. A brassica crop was identified in 15/16 cases as part of the current or recent ration.CLINICAL FINDINGS: Eight cows were found dead or died within 2 days of first signs. In eight cases death or euthanasia took place up to 3 weeks after signs were first observed. Cattle clinically examined prior to death (n=11) were generally inappetant, and recumbent or reluctant to move. Five cases had pale mucous membranes, three had petechiae and two were jaundiced. Rectal temperature was normal to sub-normal in eight cases. Evidence of melena or fresh blood at the anus or mouth was found in five cases. In three cases, alopecia and skin thickening was present, predominantly affecting the head and neck.PATHOLOGICAL FINDINGS: Petechiation of mucosal and internal serosal membranes, myocardium, subcutis and skeletal muscle was found in 10 cases. Frank haemorrhage was present in six cases, including haematomas of the subcutis, skeletal musculature, mesentery or omentum, and lumenal haemorrhage of the abomasum and/or intestine. In five cases pale nodules within myocardium and/or kidney, liver or spleen were present. Histopathologically, these were confirmed as granulomatous inflammatory lesions, which were also present within a wide range of tissues. Granulomatous foci typically comprised aggregates of macrophages, lymphocytes, plasma cells, prominent multinucleated giant cells and eosinophils.DIAGNOSIS: Idiopathic multisystemic granulomatous and haemorrhagic disease, occurring sporadically in dairy cattle, in the absence of feeds or feed additives previously associated with comparable syndromes.CLINICAL RELEVANCE: This is the first description of a novel systemic granulomatous and haemorrhagic syndrome seen in adult dairy cattle most often in their non-lactating period. The presentation can mimic important exotic disease differentials in New Zealand including anthrax, haemorrhagic septicaemia (associated with selected Pasteurella multocida strains) or infection with bovine viral diarrhoea virus type 2.

Circulation of multiple subtypes of bovine viral diarrhoea virus type 1 with no evidence for HoBi-like pestivirus in cattle herds of southern Italy

Pestiviruses of cattle include bovine viral diarrhoea 1 (BVDV-1) and 2 (BVDV-2) plus an emerging group, named HoBi-like pestivirus. In the present paper, the results of an epidemiological survey for pestiviruses circulating in cattle in southern Italy are presented. Molecular assays carried out on a total of 924 bovine samples detected 74 BVDV strains, including 73 BVDV-1 and 1 BVDV-2 viruses. Phylogenetic analysis carried out on partial 5′UTR and Npro sequences revealed the presence of 6 different subtypes of BVDV-1 and a single BVDV-2c strain. BVDV-1 displayed a high level of genetic heterogeneity, which can have both prophylactic and diagnostic implications. In addition, the detection of BVDV-2c highlights the need for a continuous surveillance for the emergence of new pestivirus strains in cattle farms in southern Italy.

Effect of modified-live bovine viral diarrhea virus type 2 vaccine on performance, health, temperature, and behavior response in high-risk beef heifer calves

The objective of this study was to determine performance, health, vaginal temperature, and behavior differences in calves vaccinated upon feedlot arrival with a multivalent modified-live virus (MLV) vaccine which included bovine viral diarrhea virus (BVDV) type 2 antigen and calves vaccinated with a vaccine which did not include BVOV type 2. Eightythree beef heifer calves were randomly assigned to receive a multivalent MLV vaccine containing either bovine herpesvirus-1, BVDV type 1, bovine respiratory syncytial virus, and parainfluenza type-3 virus (n = 42; 4-WAY), or a MLVvaccine of similar formulation which also contained a BVDV type 2 antigen (n = 41; 5-WAY). Performance outcomes were evaluated at 30 and 60 days. Vaginal temperatures were evaluated hourly and daily. Cattle behavior activity was monitored with a real-time location system. Calves in the 5-WAY group had greater average daily gain (P = 0.026) at 60 days, excluding dead animals, compared to 4-WAY group. Treatment group was not associated with vaginal temperature. Calves in 5-WAY spent a greater (P ~ 0.01) amount of time at the feed bunk on days 0, 2, 3, and 4 compared to 4-WAY. Results of this study indicate no adverse effects from administering an additional strain of BVOV type 2 to high-risk heifers. Behavioral responses indicate a potential advantage to administer 5-WAY vaccine compared to 4-WAY vaccine.

Priming Cross-Protective Bovine Viral Diarrhea Virus-Specific Immunity Using Live-Vectored Mosaic Antigens.

Bovine viral diarrhea virus (BVDV) plays a key role in bovine respiratory disease complex, which can lead to pneumonia, diarrhea and death of calves. Current vaccines are not very effective due, in part, to immunosuppressive traits and failure to induce broad protection. There are diverse BVDV strains and thus, current vaccines contain representative genotype 1 and 2 viruses (BVDV-1 & 2) to broaden coverage. BVDV modified live virus (MLV) vaccines are superior to killed virus vaccines, but they are susceptible to neutralization and complement-mediated destruction triggered by passively acquired antibodies, thus limiting their efficacy. We generated three novel mosaic polypeptide chimeras, designated NproE2123; NS231; and NS232, which incorporate protective determinants that are highly conserved among BVDV-1a, 1b, and BVDV-2 genotypes. In addition, strain-specific protective antigens from disparate BVDV strains were included to broaden coverage. We confirmed that adenovirus constructs expressing these antigens were strongly recognized by monoclonal antibodies, polyclonal sera, and IFN-γ-secreting T cells generated against diverse BVDV strains. In a proof-of-concept efficacy study, the multi-antigen proto-type vaccine induced higher, but not significantly different, IFN-γ spot forming cells and T-cell proliferation compared to a commercial MLV vaccine. In regards to the humoral response, the prototype vaccine induced higher BVDV-1 specific neutralizing antibody titers, whereas the MLV vaccine induced higher BVDV-2 specific neutralizing antibody titers. Following BVDV type 2a (1373) challenge, calves immunized with the proto-type or the MLV vaccine had lower clinical scores compared to naïve controls. These results support the hypothesis that a broadly protective subunit vaccine can be generated using mosaic polypeptides that incorporate rationally selected and validated protective determinants from diverse BVDV strains. Furthermore, regarding biosafety of using a live vector in cattle, we showed that recombinant human adenovirus-5 was cleared within one week following intradermal inoculation.

New Leaves in the Growing Tree of Pestiviruses.

Pestiviruses are a group of viruses of veterinary importance infecting livestock animals like pigs, cattle, and sheep, and also wildlife animals like wild boar and different deer species. While for decades only four classical species (Classical swine fever virus, Bovine viral diarrhea virus types 1 and 2, Border disease virus), and a few so-called atypical pestiviruses were known (e.g., Giraffe virus, Pronghorn virus, HoBi virus), a series of novel pestiviruses was identified in the last years (Bungowannah virus, Bat pestivirus, Norway rat pestivirus, Atypical porcine pestivirus, LINDA virus). The Australian Bungowannah virus could be isolated and further characterized by classical sequencing, but all the other latest novel pestiviruses were identified by metagenomics using next-generation sequencing technologies. Here, we describe these new viruses and their discovery and characterization. Differentiation is made between the occurrence of classical pestiviruses in new species and novel viruses or virus types.

Evaluation of responses to vaccination of Angus cattle for four viruses that contribute to bovine respiratory disease complex.

Although vaccination is an effective measure in reducing the risk of bovine respiratory disease complex (BRDC) in cattle, BRDC losses remain significant. Increasing the efficacy of vaccination depends on elucidating the protective immune response to different antigens included in vaccines, determining the best timing for vaccination, and understanding the impact of the age of the calf on vaccination. This study measured the serum antibodies present in calves following vaccination against 4 viruses commonly associated with BRDC: bovine viral diarrhea virus type 1 and 2 (BVDV1 and BVDV2), bovine respiratory syncytial virus (BRSV), and bovine herpesvirus 1 (BHV1). Serum antibody titers were measured in more than 1,600 calves at 3-wk intervals starting at the time of the first vaccination. This first vaccination occurred at weaning for approximately half of the individuals and 3 wk before weaning for the other half. Dam age (years), time of weaning (initial vaccination or booster vaccination), and age of calf within year-season (days within year-season) classification all were found to have a significant effect on measured traits such as the initial titer and overall response. An increased initial titer was negatively correlated with each response trait (initial, booster, and overall response). Calves that were weaned at initial vaccination had greater overall antibody response to BVDV1 and BVDV2 compared with calves weaned 3 wk before initial vaccination. In contrast, calves given their initial vaccination 3 wk before weaning had greater overall antibody response to BRSV and BHV1 compared with calves that were vaccinated at weaning. Furthermore, the circulating antibody titer at which each virus needed to be below for an individual calf to positively respond to vaccination was determined (log titer of 0.38 for BVDV1, 1.5 for BVDV2, 3.88 for BRSV, and 1.5 for BHV1). This information can be used to improve vaccination protocols to allow for a greater response rate of individuals to vaccination and, hopefully, improved protection.