Vaccination Of Calves Research Articles

Aerosol vaccination with Bacille Calmette-Guerin induces a trained innate immune phenotype in calves.

Mycobacterium bovis Bacillus Calmette-Guérin (BCG) is a live attenuated vaccine for use against tuberculosis (TB); however, it is known to reduce childhood mortality from infections other than TB. The unspecific protection induced by BCG vaccination has been associated with the induction of memory-like traits of the innate immune system identified as ‘trained’ immunity. In humans and mouse models, in vitro and in vivo BCG training leads to enhanced production of monocyte-derived proinflammatory cytokines in response to secondary unrelated bacterial and fungal pathogens. While BCG has been studied extensively for its ability to induce innate training in humans and mouse models, BCG’s nonspecific protective effects have not been defined in agricultural species. Here, we show that in vitro BCG training induces a functional change in bovine monocytes, characterized by increased transcription of proinflammatory cytokines upon restimulation with the toll-like receptor agonists. Importantly, in vivo, aerosol BCG vaccination in young calves also induced a ‘trained’ phenotype in circulating peripheral blood mononuclear cells (PBMCs), that lead to a significantly enhanced TLR-induced proinflammatory cytokine response and changes in cellular metabolism compared to PBMCs from unvaccinated control calves. Similar to the long-term training effects of BCG reported in humans, our results suggest that in young calves, the effects of BCG induced innate training can last for at least 3 months in circulating immune populations. Interestingly, however, aerosol BCG vaccination did not ‘train’ the innate immune response at the mucosal level, as alveolar macrophages from aerosol BCG vaccinated calves did not mount an enhanced inflammatory response to secondary stimulation, compared to cells isolated from control calves. Together, our results suggest that, like mice and humans, the innate immune system of calves can be ‘trained’; and that BCG vaccination could be used as an immunomodulatory strategy to reduce disease burden in juvenile food animals before the adaptive immune system has fully matured.

Short communication: Oral and intranasal administration of a modified-live Salmonella Dublin vaccine in dairy calves: Clinical efficacy and serologic response

Our objectives were to evaluate the clinical efficacy of oral and intranasal administration of a commercial modified-live Salmonella Dublin vaccine in dairy calves and to determine the serologic response associated with these extralabel routes of administration. We conducted a randomized field trial with calves from a New York dairy farm following an outbreak of Salmonella Dublin. A total of 399 Holstein calves were allocated by pen to 3 treatment groups: oral vaccination, intranasal vaccination, and an unvaccinated control group. Administration of the vaccine through oral and intranasal routes did not have a significant effect on pneumonia incidence risk or weight gain; however, calves vaccinated orally and intranasally had lower mortality risk as compared with control calves. Among calves tested using a Salmonella Dublin ELISA, vaccination did not induce an increase in antibody production relative to control calves, indicating that oral and intranasal administration will not hinder diagnosis based on this assay.

Impact of Maternal Antibody and Concurrent Vaccination on Serologic Responses to Clostridial Vaccination in Calves

At birth, one hundred and fifty beef calves were randomly assigned to one of three groups. Dams of the calves had received no vaccines for at least two years. At day sixty of age, serum was drawn for antibodies against exotoxins from Clostridium perfringens (Clp) type C and D, Cl. novyi (Cln) and Cl. sordellii (Cls). Calves in group one were administered 2ml of an intranasal vaccine containing modified live BHV-1, BRSV and PI3 virusa (IN), a modified live viral vaccine containing bovine viral diarrhea virus (BVDV) types 1 and 2 in combination with a Mannheimia hemolytica (BVDMh) inactivated leukotoxoidc and a Clostridium Chauvoei-Septicum-Novyi-Sordellii-Perfringens Types C and D Bacterin-Toxoid vaccine (7way).b Calves in group two received a systemic MLV combination vaccine containing BVDV types 1 and 2, BHV-1, BRSV, PI3 virus and the same Mh vaccined (FivewayMH). Group three were vaccinated with only the 7 way Clostridium vaccine. At 210 days of age serum was drawn and calves in group 1 received the FivewayMH and 7way vaccines. Calves in group 2 were administered the IN, BVDMH and 7way vaccines and group 3 calves were vaccinated with only the 7way. At 240 days of age sera was drawn for final SN titers. At 60 days of age high levels of maternal antibody against all the exotoxins tested were detected. Serologic responses in all groups indicated maternal antibody interference after 7way vaccination to Cl. Perfringens C and D and in group 3 to Cl. novyi and sordellii. Interference of the immune response to Cl. novyi by systemic MLV BHV-1 viral vaccination was seen on day 60 and 210 to Cl. sordellii. This study indicates that both maternal antibody and concurrent systemic BHV-1 vaccination may interfere with serologic responses to Clostridial exotoxin vaccination. The impact of the decreased antibody levels on protection could not be determined in this study.

Effect of Beta-Carotene Supplementation on the Serum Oxidative Stress Biomarker and Antibody Titer against Live Bovine Respiratory Syncytial Virus Vaccination in Japanese Black Calves.

The purpose of this study was to determine the effect of vaccination and beta-carotene supplementation on blood oxidative stress and antibody response in calves. Thirty Japanese Black calves were randomly assigned to two groups. Fifteen calves received 20 mg of beta-carotene supplemented into their daily provided rations from 2 to 8 weeks of age (BC group), and the other 15 calves did not receive the daily beta-carotene supplement (control group). All calves received a commercially available modified live bovine respiratory syncytial (RS) virus vaccine at 4 and 8 weeks of age. Blood samples were taken at 2, 4, 8, and 12 weeks of age. At 4 weeks of age, the concentration of reactive oxygen metabolites within serum were significantly lower in the BC group than the concentrations measured in the control group. Also at 4 weeks of age, the concentration of biological antioxidant capacity within serum was significantly higher in the BC group than the concentrations measured in the control group. Both groups showed a gradual decrease of antibody titers to live bovine RS virus in the samples taken from 2 to 12 weeks of age. These results confirmed that beta-carotene supplementation decreased oxidative stress. However, beta-carotene supplementation did not affect the antibody response to live bovine RS virus vaccination, perhaps due to the presence of the maternal antibody.

Herd-level risk factors associated with Brucella sero-positivity in cattle, and perception and behaviours on the disease control among agro-pastoralists in Tanzania

Brucellosis is endemic in Tanzania, particularly in agro-pastoral areas. This study investigated the herd-level sero-prevalence and risk factors for Brucella sero-positivity in cattle, and perception and behaviours associated with brucellosis control among agro-pastoralists in Morogoro Region, Tanzania. A cross-sectional study involving herd milk diagnosis by indirect enzyme-linked immunosorbent assay and questionnaire survey was conducted in 124 farms. Questions included potential risk factors, knowledge of brucellosis, willingness-to-pay for cattle vaccination, and item count technique (ICT) for selling behaviour of cows that experienced abortion. Risk factor analysis for Brucella sero-positivity in cattle and analysis of factors associated with willingness-to-pay were conducted using classical tests and generalised linear models. Most farmers had little knowledge about brucellosis (disease name: 13.7%, symptoms: 3.2%, transmission from cattle to human: 2.4%, and Brucella vaccine: 2.4%). The proportion of Brucella sero-positive herd was 44.4% (55/124, 95%CI: 35.5–53.5). No risk factors for Brucella sero-positivity were identified; however, using a veterinary service was identified as a preventive factor (OR = 0.39, 95%CI: 0.18–0.84, p = 0.02). For scenarios of vaccinating all cattle and only calves, 59.7% and 89.5% of farmers were willing to pay for vaccination, respectively. Being a Maasai tribe member was a hesitating factor for vaccinating all cattle (OR = 0.39, 95%CI: 0.19–0.83, p = 0.01) and using a veterinary service was an encouraging factor for vaccinating calves (OR = 4.0, 95%CI: 1.2–13.0, p = 0.02). The ICT found that 45.1% of farmers sold cows that experienced abortion. This estimate was not statistically different from that obtained by direct questioning (34.1%, SE = 7.5%, binomial p value = 0.27, factor score = 1.32), suggesting that farmers did not hesitate to sell such cows. The Maasai conducted more risky behaviours for human infection such as drinking raw milk (p = 0.06) or blood (p < 0.01) and helping delivery with bare hands (p = 0.03) than other tribes. Community-based brucellosis control programmes with calf vaccination may be feasible in the study areas. A One Health approach including the promotion of health education and expansion of veterinary services is crucial for disease control.

Efficacy of a recombinant Intimin, EspB and Shiga toxin 2B vaccine in calves experimentally challenged with Escherichia coli O157:H7

Escherichia coli O157:H7 is a zoonotic pathogen of global importance and the serotype of Shiga toxin-producing E.coli (STEC) most frequently associated with Hemolytic Uremic Syndrome (HUS) in humans. The main STEC reservoir is cattle. Vaccination of calves with the carboxy-terminal fraction of Intimin γ (IntC280) and EspB can reduce E.coli O157:H7 fecal shedding after experimental challenge. Shiga toxin (Stx) exerts local immunosuppressive effects in the bovine intestine and Stx2B fused to Brucella lumazine synthase (BLS-Stx2B) induces Stx2-neutralizing antibodies. To determine if an immune response against Stx could improve a vaccine’s effect on fecal shedding, groups of calves were immunized with EspB + IntC280, with EspB + IntC280 + BLS-Stx2B, or kept as controls. At 24 days post vaccination calves were challenged with E.coli O157:H7. Shedding of E.coli O157:H7 was assessed in recto-anal mucosal swabs by direct plating and enrichment followed by immunomagnetic separation and multiplex PCR. Calves were euthanized 15 days after the challenge and intestinal segments were obtained to assess mucosal antibodies. Vaccination induced a significant increase of IntC280 and EspB specific antibodies in serum and intestinal mucosa in both vaccinated groups. Antibodies against Stx2B were detected in serum and intestinal mucosa of animals vaccinated with 3 antigens. Sera and intestinal homogenates were able to neutralize Stx2 verocytotoxicity compared to the control and the 2-antigens vaccinated group. Both vaccines reduced E.coli O157:H7 shedding compared to the control group. The addition of Stx2B to the vaccine formulation did not result in a superior level of protection compared to the one conferred by IntC280 and EspB alone. It remains to be determined if the inclusion of Stx2B in the vaccine alters E.coli O157:H7 shedding patterns in the long term and after recurrent low dose exposure as occurring in cattle herds.

An Outbreak of Brucellosis in Cattle dairy farm, District Okara, Pakistan - January 2017

Background: Brucellosis is prevalent in livestock causing huge economic losses due to loss of production. On January 4, 2017, six abortions at third trimester of gestation were reported from a cattle dairy farm at Renalakhurd, District Okara. Objective: An Outbreak investigation was initiated to assess the magnitude, identify risk factors and recommend control measures. Methods: A case-control study was conducted. A case was defined as adult cow in the affected dairy farm aborting at third trimester, without fever, from 18th December 2016 to 7th January 2017. Age-matched controls were selected from the same farm (1:4). Semen doses used for insemination, were tested by molecular and culturing technique. Serological testing was done through RBPT and i-ELISA. Frequencies were calculated, odd ratios determined calculated at 95% confidence interval with p value less than 0.05. Results: A total of 49 pregnant cows were identified and 16 of them had aborted at 3rd trimester. The age ranged from 5-7 year (median=5 year). For the 16 cases attack rate was 33% for aborting cows, 24% for close contact cows. The aborting cows were more likely to have brucellosis (OR 35, 95% CI 7-175, P=0.00) as compared to non-aborting cows and close contact cows were more likely to have brucellosis (OR 5, 95% CI 1.4-16, P=0.017) as compared to cows from other sheds. A total of 18.4% (23/125) farm cattle were found infected with brucellosis on serological testing. Brucellae were not detected in semen doses. Index case was a newly added (2 month before) exotic cow that was not screened by RBPT neither quarantined. Conclusions: Infected exotic cow was the most probable cause of the outbreak. Healthy animals got infection by licking aborted fetus or vaginal secretions of aborting cow. Vaccination of eligible calves using strain19, culling of confirmed cases, isolation of pregnant cows, screening & quarantine of newly purchased animals was recommended. [iproc 2018;4(1):e10643]

Effects of injectable trace minerals on the immune response to Mannheimia haemolytica and Pasteurella multocida following vaccination of dairy calves with a commercial attenuated-live bacterin vaccine

ABSTRACT The objective was to evaluate the effects of an injectable trace mineral (ITM) supplement containing Zn, Mn, Se, and Cu on the humoral and cell mediated immune responses to vaccine antigens in dairy calves receiving an attenuated-live bacterin vaccine containing Mannheimia haemolytica and Pasteurella multocida. Thirty 3-mo-old dairy calves received 2 doses (21 d apart) of an attenuated-live M. haemolytica and P. multocida bacterin vaccine (Once PMH, Merck Animal Health, Summit, NJ), and a 5-way modified-live-virus vaccine (Express 5, Boehringer Ingelheim, Vetmedica, St. Joseph, MO). On the day of primary vaccination, animals were randomly assigned to 1 of the 2 treatment groups (n = 15 per group): ITM (ITM administration) or control (sterile saline injection). Treatments were administered concurrently with vaccinations. Blood samples were collected for determination of antibody titers against M. haemolytica and P. multocida and of antigen-induced proliferation and interferon-γ secretion by peripheral blood mononuclear cells. Serum Se and Mn concentrations were greater (P 0.05) between groups. The use of ITM with bovine respiratory disease vaccines enhanced (P

Effect of suckler cow vaccination against glycoprotein E (gE)-negative bovine herpesvirus type 1 (BoHV-1) on passive immunity and physiological response to subsequent bovine respiratory disease vaccination of their progeny

The study objectives were: 1) to characterise the development of immunocompetence in beef suckler calves from birth to three months of age, and 2) to trace glycoprotein E (gE)-negative bovine herpesvirus type 1 (BoHV-1) antibodies from dam to calf and subsequent vaccination against pneumonia. Thirty multiparous beef suckler, spring-calving cows, consisting of two genotypes were involved; Limousin×Friesian (LF) and Charolais×Limousin (CL). Cows were immunised against the inactivated antigen strain of BoHV-1 (gE- (IBR marker vaccine) at day −84 and received a booster at day −56 relative to the expected calving date (d 0). Calves were immunised at 14 and 42days of age against PI-3 virus, BRSV and Mannheimia (Pasteurella) haemolytica serotype A1 using a commercial vaccine administered subcutaneously. Additionally, calves were immunised against BoHV-1 at 42days of age, using 1 dose of a live commercial vaccine administered intranasally. Blood samples were collected from all calves (n=30) via jugular venipuncture at birth, prior to colostrum feeding (0h), at 12h (h), 24h, 72h and 168h after the initial feeding of colostrum, and at d 7, 14, 28, 42, 56 and 84 post birth. The mean ratio of gE negative antibodies circulating in the blood of LF and CL dams pre-partum scored negative to gE ab (S/N≥0.70). Antibody levels of BoHV-1 (wild type (wt)) peaked at 12h post-birth in calves and declined thereafter, as the maternal antibodies decayed. There was no difference in BoHV-1 and BRSV antibody levels in calves post vaccination.

Effect of passive transfer status on response to a glycoprotein E (gE)-negative bovine herpesvirus type 1 (BoHV-1) and bovine respiratory syncytial virus (BRSV) vaccine and weaning stress in pre-weaned dairy calves

ABSTRACTThe study objectives were to: 1) examine how calves of divergent immune status respond to BRSV vaccination at 3 weeks of age; 2) trace glycoprotein E negative BoHV-1 antibodies from vaccinated dams to calf sera and to investigate how passive transfer affects response to live BoHV-1 vaccine at 6 weeks of age; 3) explore the impact of passive transfer status on blood metabolites around weaning. Thirty seven Holstein cows and their calves were included in the study. All cows were immunised with a commercial marker vaccine against BoHV-1(gE-) administered intra-muscularly at 4 month prior to the start of calving. Calves were assigned to 1 of 2 colostrum treatment groups: 1) 5% of BW in colostrum fed at birth, or 2) 10% of BW in colostrum fed at birth. Calves were also immunised at 3 weeks of age with a respiratory commercial vaccine, and a booster administered 4 weeks later. Calves were also immunised against BoHV-1 at 6 weeks of age, using one dose of a live commercial vaccine. The results demonstrated that level of passive immunity had no effect on immune response to vaccination and the importance of feeding colostrum from vaccinated BoHV-1 gE- dams to provide calves with passive protection against IBRV.

Abortions in an organized dairy farm from North India reveal the possibility of breed susceptibility to Bovine Brucellosis

The present study was undertaken over a three year period (2012–2014) in an organized dairy farm located in North India to ascertain Brucella abortus as the putative cause of abortion. The dairy farm maintained cattle of Frieswal, Crossbred and Sahiwal breeds and followed calf-hood vaccination with Brucella abortus Strain 19 live vaccine in all the heifers. Even with the recommended vaccination schedule and good managemental practices in place, 88 cases of abortions clinically suspected of bovine brucellosis (40 from Frieswal breed, 17 from Crossbred cattle and 31 from Sahiwal breed) were reported from this farm. From these abortion cases, bacteriological isolation was possible in only four dams while 16 dams were found to be serologically positive in Serum Tube Agglutination Test (STAT). Molecular screening by PCR assay (specific for the bcsp31 gene of B. abortus) revealed that 24 dams were positive, out of which 20 were from Frieswal breed and rest four were from Crossbred herd. Prominently, all Sahiwal dams were found to be negative in bacteriological isolation and also in PCR assay. These results thus indicate towards the possibility of breed predisposition to abortions due to B. abortus infection. Statistical analysis by Fischer exact test (p<0.01) too substantiated that breed susceptibility exists among these PCR positive cases. This study is novel as breed variation in abortions due to B. abortus in cattle is being documented for the first time. Seven representative PCR amplicons generated during the study were also sequenced and submitted to NCBI GenBank. Moreover, this study also accentuates the importance of PCR screening especially in vaccinated herd and raises concerns on over-dependence of serological assays when intensive vaccination is practised without any concomitant DIVA strategy. Thus, besides assisting in planning pragmatic control strategies against bovine brucellosis these findings are also imperative from ‘One Health’ context, also.

Intranasal immunization with a recombinant outer membrane protein H based Haemorrhagic septicemia vaccine in dairy calves.

Haemorrhagic septicemia (HS) is a contagious disease in cattle with high morbidity and mortality rates. HS vaccine in Thailand is an oil-adjuvant formulation, and is difficult to administer. The present study aimed to formulate and evaluate the protection in dairy calves conferred by immunization with an in-house intranasal HS vaccine. The intranasal vaccine was formulated in a total volume of 500 µl containing either 50 or 100 µg of the recombinant outer membrane protein H (rOmpH) of Pasteurella multocida strain M-1404 (serovar B:2), and 10 µg of Cytosine-phosphate-guanosine oligodeoxynucleotides (CpG-ODN) as a mucosal adjuvant. Intranasal immunizations were conducted three times at three-week intervals. The antibodies post-immunization were detected by indirect ELISA and demonstrated efficient in vitro activity in suppressing a P. multocida strain from the complement-mediated killing assay. An intranasal vaccine induced both the serum IgG and secretory IgA levels that were significantly higher than the level conferred by the parenteral vaccine (P<0.05). Challenge exposure was conducted with a P. multocida strain M-1404 at day 72 of the experiments. The immunized calves had reduced clinical signs after challenge exposure that would normally result in disease proliferation. We conclude that intranasal vaccination of calves with rOmpH with CpG-ODN 2007 stimulated serum and secretory antibodies to rOmpH and whole cells of P. multocida strain M-1404 antigen. Moreover, it would result in protection in calves against artificial P. multocida infection.

Quantification of the probability of reintroduction of IBR in the Netherlands through cattle imports

In the Netherlands, the feasibility of a national control program for infectious bovine rhinotracheitis (IBR) is discussed. The aim of this program would be to achieve freedom from BoHV1 circulation (the causal agent of IBR), in the Dutch cattle population. When IBR would be eradicated, maintaining the free status is essential and insight in the probability of introduction of IBR through cattle imports is crucial. Values for input parameters such as the number of imports per country of origin, herd level prevalence and probability that a random imported animal per age category was either acutely or latently infected with IBR were quantified. A stochastic simulation model was built to predict the basic risk and the efficacy of four risk mitigating scenarios were evaluated. These scenarios involved testing prior to import, import restrictions and vaccination. The model output predicted that IBR infected animals are imported regularly. In an IBR free situation, 571 (5th and 95th percentile: 431–781) cattle herds will be newly infected. Latent infections account for most newly infected herds (77%). When the virus in the imported latently infected animal does not reactivate, subsequent impact of such infections remains limited. The model predicted that most of the herds infected by introduction of acutely infected animals would be veal herds. The scenario in which imports were only allowed from status 9 or 10 countries combined with testing cattle that originated from status 9 countries was most effective in reduction of the import risk to 70 herds per year. The scenario in which vaccination of calves was combined with testing of older cattle was estimated to reduce the number of newly infected herds to 82 per year. The stakeholders classified the latter scenario as most realistic because this scenario was deemed both feasible and rather effective. This study did not evaluate the impact of introduction of IBR in the cattle population, which might differ depending on the type of infection (acute vs. latent) and the herd type in which the virus is introduced. Moreover, when making the final decision about the optimal intervention, the economic perspective should also be taken into account. This study predicted that introduction of IBR will remain a risk for the Dutch cattle population after virus circulation is eliminated from the Netherlands. The import risk is reduced most in scenarios in which testing and vaccination are combined.

Safety of vaccination against brucellosis with the rough strain in pregnant cattle.

Brucellosis is an infectious and contagious disease that profoundly impacts public health. However, in many countries, disease prevention is restricted to the vaccination of calves, and there is no prophylactic strategy for pregnant heifers and cows. The aim of this study was to evaluate the safety of the rough strain vaccine against brucellosis in pregnant cattle. Crossbred cows (N=96) at three gestational periods (early, mid, or late pregnancy) were randomly allocated into the vaccine treatment group or to the control group. We then compared the percentage of pregnancies reaching full term, live calves 60days after delivery, and seropositive calves. There was no effect of vaccination in any of the gestational periods on the evaluation endpoints. In conclusion, vaccination against brucellosis with the rough strain is safe for pregnant cattle at all gestational periods.

Virus detection by PCR following vaccination of naive calves with intranasal or injectable multivalent modified-live viral vaccines.

We evaluated duration of PCR-positive results following administration of modified-live viral (MLV) vaccines to beef calves. Twenty beef calves were randomly assigned to either group 1 and vaccinated intranasally with a MLV vaccine containing bovine alphaherpesvirus 1 (BoHV-1), bovine respiratory syncytial virus (BRSV), and bovine parainfluenza virus 3 (BPIV-3), or to group 2 and vaccinated subcutaneously with a MLV vaccine containing bovine viral diarrhea virus 1 and 2 (BVDV-1, -2), BoHV-1, BRSV, and BPIV-3. Deep nasopharyngeal swabs (NPS) and transtracheal washes (TTW) were collected from all calves, and whole blood was collected from group 2 calves and tested by PCR. In group 1, the proportions of calves that tested PCR-positive to BVDV, BoHV-1, BRSV, and BPIV-3 on any sample at any time were 0%, 100%, 100%, and 10%, respectively. In group 1 calves, 100% of calves became PCR-positive for BoHV-1 by day 3 post-vaccination and 100% of calves became PCR-positive for BRSV by day 7 post-vaccination. In group 2, the proportions of calves that tested positive to BVDV, BoHV-1, BRSV, and BPIV-3 on any sample at any time were 50%, 40%, 10%, and 0%, respectively. All threshold cycle (Ct) values were >30 in group 2 calves, irrespective of virus; however, Ct values <25 were observed in group 1 calves from PCR-positive results for BoHV-1 and BRSV. All calves were PCR-negative for all viruses after day 28. Following intranasal MLV viral vaccination, PCR results and Ct values for BRSV and BoHV-1 suggest that attempts to differentiate vaccine virus from natural infection is unreliable.

Efficacy and immunogenicity of a novel polyanhydride nanovaccine for use against RSV infection in the neonate

Abstract Respiratory syncytial virus (RSV) is a leading cause of severe acute lower respiratory tract infection in infants and children worldwide. Bovine RSV (BRSV) is closely related to human RSV and a significant cause of morbidity in young cattle. BRSV infection in calves displays many similarities to RSV infection in humans, including similar age dependency, gross and microscopic pathology, and innate and adaptive immune responses. The poor immunogenicity of RSV has been a complicating factor in the development of a safe and effective vaccine in both humans and calves. Polyanhydride nanovaccines (i.e. nanoparticle-based vaccines) have shown promise as adjuvants and vaccine delivery vehicles in rodent models due to their ability to promote enhanced immunogenicity through both the route of administration and the ability to provide sustained antigen exposure. In these studies, we determined the efficacy of a novel polyanhydride nanovaccine containing the stable, post-fusion F and G glycoproteins from BRSV, against RSV infection using a neonatal calf model. In vitro, the BRSV nanovaccine induced activation and cytokine secretion by monocyte-derived dendritic cells and alveolar macrophages. In vivo, calves receiving the BRSV F/G nanovaccine, followed by aerosol challenge with BRSV, demonstrated increased virus-specific IgA in the nasal and bronchoalveolar lavage fluid, an increase in RSV-specific cellular responses in the peripheral blood and airways, and a reduction in BRSV shedding compared to unvaccinated control calves. Our results suggest that the RSV-F/G nanovaccine is highly immunogenic and with optimization, has the potential to significantly reduce the disease burden associated with RSV infection in both humans and animals.

Development and Function of the Mucosal Immune System in the Upper Respiratory Tract of Neonatal Calves.

Respiratory infections remain the second most common cause of clinical disease and mortality in newborn calves, which has led to increased interest in using vaccines early in life to mitigate this risk. Intranasal vaccination of neonatal calves can be an effective strategy to circumvent vaccine interference by maternal antibody, but this raises questions regarding onset of immune competence in the upper respiratory tract (URT) following birth. Little is known, however, about the development and function of mucosa-associated lymphoid tissue (MALT) in the URT of newborn calves and what factors, including the commensal microbiome, contribute to this early development. We review the structure, development, and function of MALT in the bovine URT during the first six weeks of life and identify knowledge gaps regarding this early developmental time. This information is critical when designing vaccination programs for young calves, especially when targeting respiratory pathogens that may reside within the commensal microbiome.

Integrated analysis of recombinant BPV-1 L1 protein for the production of a bovine papillomavirus VLP vaccine

Bovine papillomatosis is an infectious disease that is caused by bovine papillomavirus (BPV), which results in important economic losses. However, no BPV vaccines or effective treatment methods are commercially available to date. Moreover, the absence of papillomavirus replication in vitro makes the use of recombinant protein a promising candidate for vaccine formulations. Hence, we developed an integrated study on the L1 capsid protein of BPV-1, obtained from a bacterial expression system, regarding its purification, biosafety, thermostability and immunogenicity. The results indicated an absence of genotoxicity of the purified recombinant L1 protein, β-sheet prevalence of secondary structure folding, protein stability under high temperatures as well as the presence of capsomeres and VLPs. In addition, preliminary experimental vaccination of calves showed the production of specific antibodies against BPV-1 L1.

Vaccination of calves with Mycobacterium bovis Bacillus Calmette-Guerin reduces the frequency and severity of lesions of bovine tuberculosis under a natural transmission setting in Ethiopia.

SummaryBovine tuberculosis (bTB) is highly prevalent in intensive dairy farms of the urban “milk‐sheds” in Ethiopia, and vaccination could be a cost‐effective disease control strategy. In the present study, the efficacy of Bacillus Calmette–Guerin (BCG) to protect against bTB was assessed in Holstein–Friesian calves in a natural transmission setting. Twenty‐three 2‐week‐old calves were subcutaneously vaccinated with BCG Danish SSI strain 1331, and matched 26 calves were injected with placebo. Six weeks later, calves were introduced into a herd of M. bovis‐infected animals (reactors) and kept in contact with them for 1 year. In vitro and in vivo immunological tests were performed to assess immune responses post‐vaccination and during exposure. Successful vaccine uptake was confirmed by tuberculin skin test and IFN‐γ responses in vaccinated calves. The kinetics of IFN‐γ responses to early secretory antigen target 6 and culture filtrate protein 10 (ESAT6 and CFP10, respectively) and tuberculin skin test responses post‐exposure suggested that the animals were infected early after being placed in contact with the infected herd as immunological signs of infection were measurable between 2 and 4 months post‐initial exposure. Protection was determined by comparing gross and microscopic pathology and bacteriological burden between vaccinated and control calves. BCG vaccination reduced the proportions of tissues with visible pathology in vaccinates compared to control calves by 49% (p < .001) with 56%, 43%, 72%, and 38% reductions in the proportion of lesioned tisues in head, thoracic, abdominal lymph nodes, and lungs, respectively (p‐values .029–.0001). In addition, the lesions were less severe grossly and microscopically in vaccinated calves than in non‐vaccinated calves (p < .05). The reduction in the overall incidence rates of bTB was 23%, 28%, and 33% on the basis of the absence of gross pathology, M. bovis culture positivity, and histopathology, respectively, in vaccinated animals. In conclusion, BCG vaccination reduced the frequency and severity of the pathology of bTB significantly, which is likely to reduce onwards transmission of the disease.

Non-toxic perfringolysin O and α-toxin derivatives as potential vaccine candidates against bovine necrohaemorrhagic enteritis

Bovine necrohaemorrhagic enteritis is a fatal Clostridium perfringens type A-induced disease that is characterised by sudden death. Recently the involvement of perfringolysin O and α-toxin in the development of necrohaemorrhagic lesions in the gut of calves was suggested, and thus derivatives of these toxins are potentially suitable as vaccine antigens. In the current study, the perfringolysin O derivative PFOL491D, alone or in combination with α-toxin derivative GST-cpa247-370, was evaluated as possible vaccine candidate, using in vitro assays.PFOL491D showed no haemolytic effect on horse red blood cells and no cytotoxic effect on bovine endothelial cells. Furthermore, calves immunised with PFOL491D raised antibodies against perfringolysin O that could inhibit the perfringolysin O-associated haemolytic activity on horse red blood cells. Antisera from calves immunised with PFOL491D had a significantly higher neutralising capacity against the cytotoxic effect of C. perfringens culture supernatant to bovine endothelial cells than serum from control calves (P < 0.05). Immunisation of calves with PFOL491D in combination with GST-cpa247-370 elicited antibodies against perfringolysin O and α-toxin and consequently inhibited both the perfringolysin O-associated haemolytic activity and the α-toxin-associated lecithinase activity in vitro. Additionally, the neutralising ability of these antisera on the cytotoxic effect of C. perfringens culture supernatant to bovine endothelial cells was significantly higher than that from calves immunised with PFOL491D (P < 0.001). In conclusion, perfringolysin O derivative PFOL491D is an immunogenic antigen that can potentially be used to produce vaccine against bovine necrohaemorrhagic enteritis. Including α-toxin derivative GST-cpa247-370 has an additional protective effect and therefore vaccination of calves with a combination of both antigens seems even more promising.