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Krishnagopal A, van Drunen Littel-van den Hurk S. The biology and development of vaccines for bovine alphaherpesvirus 1. Vet J 2024; 306:106152. [PMID: 38821207 DOI: 10.1016/j.tvjl.2024.106152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2023] [Revised: 05/26/2024] [Accepted: 05/27/2024] [Indexed: 06/02/2024]
Abstract
Bovine alphaherpesvirus type 1 (BoAHV-1) infections lead to compromised herd health and significantly reduced productivity of affected cattle. While BoAHV-1 may cause rhinotracheitis, conjunctivitis, genital infections, and abortions, respiratory tract infections constitute the predominant clinical disease. Immune suppression induced by BoAHV-1 may contribute to co-infections initiating the bovine respiratory disease complex. In this review, the emphasis is to recapitulate the biology and the vaccine technologies currently in use and in development for BoAHV-1, and to discuss the major limitations. Studies on the life cycle and host interactions of BoAHV-1 have resulted in the identification of virulence factors. While several vaccine types, such as vectored vaccines and subunit vaccines, are under investigation, modified live and inactivated BoAHV-1 vaccines are still most frequently used in most areas of the world, whereas attenuated and inactivated marker vaccines are in use in Europe. The knowledge gained from studies on the biology of BoAHV-1 can form a basis for the rational design of future vaccines.
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Affiliation(s)
- Akshaya Krishnagopal
- Biochemistry, Microbiology and Immunology, College of Medicine, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada; Vaccine and Infectious Disease Organization, University of Saskatchewan, Saskatoon, SK S7N 5E3, Canada
| | - Sylvia van Drunen Littel-van den Hurk
- Biochemistry, Microbiology and Immunology, College of Medicine, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada; Vaccine and Infectious Disease Organization, University of Saskatchewan, Saskatoon, SK S7N 5E3, Canada.
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Chicoski LM, Fritzen JTT, Lorenzetti E, da Costa AR, Moro E, de Carvalho ER, Alfieri AF, Alfieri AA. Serological profile of respiratory viruses in unvaccinated steers upon their arrival at Brazilian feedlot facilities. Braz J Microbiol 2023; 54:3237-3244. [PMID: 37700145 PMCID: PMC10689696 DOI: 10.1007/s42770-023-01122-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Accepted: 08/31/2023] [Indexed: 09/14/2023] Open
Abstract
Bovine viral diarrhea virus (BVDV), bovine alphaherpesvirus 1 (BoAHV1), bovine respiratory syncytial virus (BRSV), and bovine parainfluenza virus 3 (BPIV-3) are involved in bovine respiratory disease. These viruses can infect the respiratory system and cause considerable economic losses to beef and dairy cattle herds. This study aimed to determine the serological profiles of steers for BVDV, BoAHV1, BRSV, and BPIV-3 upon their arrival at Brazilian feedlot facilities. A total of 1,282 serum samples from unvaccinated steers were obtained on the first day of feeding. Samples were collected from 31 beef cattle herds reared in an extensive rearing system in six Brazilian states. Antibodies against BVDV, BoAHV1, BRSV, and BPIV-3 were detected using a virus neutralization test. The steers were distributed in agreement with their age and the Brazilian state of origin. The highest seropositivity was for BoAHV1 and BPIV-3 at 92.1% (1,154/1,253) and 86.6% (1,100/1,270), respectively. The seropositivity of BRSV was 77.1% (959/1,244). BVDV presented a lower rate, at slightly more than 50% (51.8%; 656/1,266). Age was a risk factor for the presence of antibodies against BVDV, BoAHV1, and BPIV-3 but not BRSV. A positive correlation was identified between BoAHV1 and BPIV-3 (P = 0.85) and between BRSV and BPIV-3 (P = 0.47). The high rate of seropositive steers for these four respiratory viruses on the first day of confinement identified in this serological survey provides important epidemiological information on respiratory infections, as the seropositivity of the four main bovine respiratory viruses in Brazilian beef cattle herds in an extensive rearing system.
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Affiliation(s)
- Larissa Melo Chicoski
- Laboratory of Animal Virology, Department of Veterinary Preventive Medicine, Universidade Estadual de Londrina, Celso Garcia Cid Road, PR455 Km 380, PO Box 10011, Londrina, Paraná, 86057-970, Brazil
| | - Juliana Torres Tomazi Fritzen
- Laboratory of Animal Virology, Department of Veterinary Preventive Medicine, Universidade Estadual de Londrina, Celso Garcia Cid Road, PR455 Km 380, PO Box 10011, Londrina, Paraná, 86057-970, Brazil
| | - Elis Lorenzetti
- Laboratory of Animal Virology, Department of Veterinary Preventive Medicine, Universidade Estadual de Londrina, Celso Garcia Cid Road, PR455 Km 380, PO Box 10011, Londrina, Paraná, 86057-970, Brazil
- Post Graduate Program in Animal Health and Production, Universidade Pitágoras Unopar Anhanguera, Arapongas, Paraná, Brazil
| | - Arthur Roberto da Costa
- Laboratory of Animal Bacteriology, Department of Veterinary Preventive Medicine, Universidade Estadual de Londrina, Londrina, Paraná, Brazil
| | - Elio Moro
- Zoetis, São Paulo, São Paulo, Brazil
| | | | - Alice Fernandes Alfieri
- Laboratory of Animal Virology, Department of Veterinary Preventive Medicine, Universidade Estadual de Londrina, Celso Garcia Cid Road, PR455 Km 380, PO Box 10011, Londrina, Paraná, 86057-970, Brazil
- Multi-User Animal Health Laboratory, Molecular Biology Unit, Department of Veterinary Preventive Medicine, Universidade Estadual de Londrina, Londrina, Paraná, Brazil
| | - Amauri Alcindo Alfieri
- Laboratory of Animal Virology, Department of Veterinary Preventive Medicine, Universidade Estadual de Londrina, Celso Garcia Cid Road, PR455 Km 380, PO Box 10011, Londrina, Paraná, 86057-970, Brazil.
- Multi-User Animal Health Laboratory, Molecular Biology Unit, Department of Veterinary Preventive Medicine, Universidade Estadual de Londrina, Londrina, Paraná, Brazil.
- National Institute of Science and Technology for Dairy Production Chain (INCT-LEITE), Universidade Estadual de Londrina, Londrina, Brazil.
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Hoyos-Jaramillo A, Palomares R, Bittar J, Divers S, Chamorro M, Berghaus R, Kirks S, Rush J, Edmondson M, Rodriguez A, Gonzalez-Altamiranda E. Clinical status and endoscopy of the upper respiratory tract of dairy calves infected with Bovine viral diarrhea virus 2 and Bovine herpes virus 1 after vaccination and trace minerals injection. Res Vet Sci 2022; 152:582-595. [DOI: 10.1016/j.rvsc.2022.09.026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 09/19/2022] [Accepted: 09/23/2022] [Indexed: 11/24/2022]
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Parenteral Antioxidant Supplementation at Birth Improves the Response to Intranasal Vaccination in Newborn Dairy Calves. Antioxidants (Basel) 2021; 10:antiox10121979. [PMID: 34943082 PMCID: PMC8750176 DOI: 10.3390/antiox10121979] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 12/09/2021] [Accepted: 12/10/2021] [Indexed: 11/17/2022] Open
Abstract
Newborn calves experience oxidative stress throughout the first month of their life, which is known to decrease lymphocyte functions relevant to vaccine responsiveness. Thus, this study aimed to determine the extent to which parenteral antioxidant supplementation given at birth improves the response to an intranasal viral vaccine in the first month of life of newborn dairy calves. For this, 21 calves were randomly assigned at birth to one of two commercially available antioxidant micronutrient supplements or a placebo group receiving 0.9% sterile saline (n = 7/group). Serum and nasal secretion samples were collected before administration of treatments and an intranasal vaccine against respiratory viruses (bovine herpesvirus type 1, bovine syncytial respiratory virus, and parainfluenza 3), and once weekly for the first four weeks of age. Systemic redox balance was determined in serum. Immunoglobulin A specific for bovine herpesvirus 1 and bovine syncytial respiratory virus was quantified in nasal secretions as a proxy to intranasal vaccine responsiveness. Our results showed that parenteral administration of antioxidants at birth improved calves' redox balance. Additionally, calves receiving antioxidant supplementation had higher concentrations of immunoglobulin A in their nasal secretions than calves in the control group. Thus, we conclude that supplementation of calves with antioxidants at birth could be a practical strategy to improve intranasal vaccine response. Future larger studies should evaluate the extent to which this increased mucosal response to intranasal vaccination could result in decreased calf morbidity and mortality.
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Lemon JL, McMenamy MJ. A Review of UK-Registered and Candidate Vaccines for Bovine Respiratory Disease. Vaccines (Basel) 2021; 9:vaccines9121403. [PMID: 34960149 PMCID: PMC8703677 DOI: 10.3390/vaccines9121403] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Revised: 11/10/2021] [Accepted: 11/22/2021] [Indexed: 01/11/2023] Open
Abstract
Vaccination is widely regarded as a cornerstone in animal or herd health and infectious disease management. Nineteen vaccines against the major pathogens implicated in bovine respiratory disease are registered for use in the UK by the Veterinary Medicines Directorate (VMD). However, despite annual prophylactic vaccination, bovine respiratory disease is still conservatively estimated to cost the UK economy approximately £80 million per annum. This review examines the vaccine types available, discusses the surrounding literature and scientific rationale of the limitations and assesses the potential of novel vaccine technologies.
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Affiliation(s)
- Joanne L. Lemon
- Sustainable Agri-Food and Sciences Division, Agri-Food and Bioscience Institute, Newforge Lane, Belfast BT9 5PX, UK
- Correspondence:
| | - Michael J. McMenamy
- Veterinary Sciences Division, Agri-Food and Bioscience Institute, Stormont, Belfast BT4 3SD, UK;
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Bornheim HN, Chamorro MF, Cernicchiaro N, Reppert EJ, Larson RL, Huser S, Thoresen M, Jones K, Weaber RL, Woolums AR. Evaluation of specific immunoglobulin A in nasal secretions and neutralizing antibodies in serum collected at multiple time points from young beef calves following intranasal or subcutaneous administration of a modified-live bovine respiratory syncytial virus vaccine. Am J Vet Res 2021; 82:746-751. [PMID: 34432517 DOI: 10.2460/ajvr.82.9.746] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To determine anti-bovine respiratory syncytial virus (BRSV) antibody titers for nasal secretions and serum from beef calves following administration of a modified-live (MLV) BRSV vaccine. ANIMALS 60 healthy newborn purebred beef calves. PROCEDURES Calves were randomly assigned to 1 of 3 groups: intranasal (IN)-SC (IN MLV BRSV vaccine within 24 hours of birth and SC MLV BRSV vaccine at 2 months of age), SC-IN (SC MLV BRSV vaccine within 24 hours of birth and IN MLV BRSV vaccine at 2 months of age), or NO-IN (no vaccine within 24 hours of birth and IN MLV BRSV vaccine at 2 months of age). Nasal secretion and serum samples were collected for determination of anti-BRSV antibodies within 24 hours of birth and 2 and 6 months of age. RESULTS Titers of anti-BRSV IgA antibodies in nasal secretions and BRSV neutralizing antibodies in serum were similar among groups at each sampling time. Within 24 hours of birth, nasal anti-BRSV IgA titers were negligible. At 2 months, mean nasal anti-BRSV IgA titers for calves in IN-SC, SC-IN, and NO-IN groups were 192.84, 224.49, and 114.71, respectively. CONCLUSIONS AND CLINICAL RELEVANCE Concentrations of anti-BRSV IgA antibodies in the nasal secretions and BRSV neutralizing antibodies in the serum of young beef calves following an MLV BRSV vaccine protocol that consisted of IN or SC vaccine within 24 hours of birth and vice versa at 2 months of age were not different from that following only an IN MLV BRSV vaccine at 2 months of age. However, the lack of any differences may have been attributed to other factors.
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Affiliation(s)
- Heather N Bornheim
- From the Departments of Clinical Sciences, College of Veterinary Medicine, Kansas State University, Manhattan, KS 66506
| | - Manuel F Chamorro
- From the Department of Clinical Sciences, College of Veterinary Medicine, Auburn University, Auburn, AL 36849 (Chamorro)
| | - Natalia Cernicchiaro
- From the Diagnostic Medicine and Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS 66506
| | - Emily J Reppert
- From the Departments of Clinical Sciences, College of Veterinary Medicine, Kansas State University, Manhattan, KS 66506
| | - Robert L Larson
- From the Departments of Clinical Sciences, College of Veterinary Medicine, Kansas State University, Manhattan, KS 66506
| | - Shaun Huser
- From the Departments of Clinical Sciences, College of Veterinary Medicine, Kansas State University, Manhattan, KS 66506
| | - Merrilee Thoresen
- From the Departments of Pathobiology and Population Medicine, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS 39762 (Thoresen, Jones, Woolums)
| | - Katherine Jones
- From the Departments of Pathobiology and Population Medicine, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS 39762 (Thoresen, Jones, Woolums)
| | - Robert L Weaber
- From the Animal Sciences and Industry (Weaber), College of Veterinary Medicine, Kansas State University, Manhattan, KS 66506
| | - Amelia R Woolums
- From the Departments of Pathobiology and Population Medicine, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS 39762 (Thoresen, Jones, Woolums)
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Palomares RA, Bittar JHJ, Woolums AR, Hoyos-Jaramillo A, Hurley DJ, Saliki JT, Ferrer MS, Bullington AC, Rodriguez A, Murray T, Thoresen M, Jones K, Stoskute A. Comparison of the immune response following subcutaneous versus intranasal modified-live virus booster vaccination against bovine respiratory disease in pre-weaning beef calves that had received primary vaccination by the intranasal route. Vet Immunol Immunopathol 2021; 237:110254. [PMID: 34034143 DOI: 10.1016/j.vetimm.2021.110254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 04/23/2021] [Accepted: 05/02/2021] [Indexed: 11/29/2022]
Abstract
This study was performed to elucidate whether the route of booster vaccination affects the immune response against respiratory vaccine viruses in pre-weaning beef calves that receive primary intranasal (IN) vaccination during the first month of life. The objective was to compare the serum neutralizing antibody (SNA) titers to BHV1, BRSV, and BPI3V, cytokine mRNA expression and mucosal BHV1- and BRSV-specific IgA in nasal secretions following administration of IN or subcutaneous (SC) modified-live virus (MLV) booster vaccines 60 days after primary IN vaccination in young beef calves. Twenty-one beef calves were administered 2 mL of an IN MLV vaccine containing BHV1, BRSV, and BPI3V (Inforce3®) between one and five weeks of age. Sixty days after primary vaccination, calves were randomly assigned to one of two groups: IN-MLV (n = 11): Calves received 2 mL of the same IN MLV vaccine used for primary vaccination and 2 mL of a SC MLV vaccine containing BVDV1 & 2 (Bovi- Shield GOLD® BVD). SC-MLV (n = 10): Calves were administered 2 mL of a MLV vaccine containing, BHV1, BRSV, BPI3V, and BVDV1 & 2 (Bovi-Shield GOLD® 5). Blood and nasal secretion samples were collected on days -61 (primary vaccination), -28, -14, 0 (booster vaccination), 14, 21, 28, 42 and 60 for determination of SNA titers, cytokine gene expression analysis and nasal virus-specific IgA concentrations. Statistical analysis was performed using a repeated measures analysis through PROC GLIMMIX of SAS®. Booster vaccination by neither IN nor SC routes induced a significant increase in SNA titers against BHV1, BRSV, and BPI3V. Subcutaneous booster vaccination induced significantly greater BRSV-specific SNA titers (on day 42) and IgA concentration in nasal secretions (on days 21 and 42) compared to calves receiving IN booster vaccination. Both IN and SC booster vaccination were able to stimulate the production of BHV1-specific IgA in nasal secretions. In summary, booster vaccination of young beef calves using either SC or IN route two months after IN MLV primary vaccination resulted in comparable SNA titers, cytokine gene expression profile and virus-specific IgA concentration in nasal secretions. Only a few differences in the systemic and mucosal immune response against BHV1 and BRSV were observed. Subcutaneous booster vaccination induced significantly greater BRSV-specific SNA and secretory IgA titers compared to IN booster vaccination.
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Affiliation(s)
- Roberto A Palomares
- Group for Reproduction in Animals, Vaccinology and Infectious Diseases (GRAVID™), College of Veterinary Medicine, University of Georgia, Athens, GA 30602-2771, United States; Department of Population Health, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, United States; Department of Large Animal Medicine, College of Veterinary Medicine, University of Georgia, Athens, GA 30602-2771, United States.
| | - João H J Bittar
- Group for Reproduction in Animals, Vaccinology and Infectious Diseases (GRAVID™), College of Veterinary Medicine, University of Georgia, Athens, GA 30602-2771, United States; Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL 32610, United States
| | - Amelia R Woolums
- Department of Pathobiology and Population Medicine, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS, United States
| | - Alejandro Hoyos-Jaramillo
- Group for Reproduction in Animals, Vaccinology and Infectious Diseases (GRAVID™), College of Veterinary Medicine, University of Georgia, Athens, GA 30602-2771, United States; Department of Population Health, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, United States
| | - David J Hurley
- Department of Population Health, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, United States; Department of Large Animal Medicine, College of Veterinary Medicine, University of Georgia, Athens, GA 30602-2771, United States
| | - Jeremiah T Saliki
- Oklahoma Animal Disease Diagnostic Laboratory, College of Veterinary Medicine, Oklahoma State University, Stillwater, OK 74078, United States
| | - Maria S Ferrer
- Group for Reproduction in Animals, Vaccinology and Infectious Diseases (GRAVID™), College of Veterinary Medicine, University of Georgia, Athens, GA 30602-2771, United States; Department of Large Animal Medicine, College of Veterinary Medicine, University of Georgia, Athens, GA 30602-2771, United States
| | - Anna C Bullington
- Department of Large Animal Medicine, College of Veterinary Medicine, University of Georgia, Athens, GA 30602-2771, United States
| | - Adriana Rodriguez
- Group for Reproduction in Animals, Vaccinology and Infectious Diseases (GRAVID™), College of Veterinary Medicine, University of Georgia, Athens, GA 30602-2771, United States; Department of Population Health, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, United States
| | - Tyler Murray
- Department of Animal and Dairy Sciences, College of Agriculture and Environmental Sciences, University of Georgia, Athens, GA 30602-2771, United States
| | - Merrilee Thoresen
- Department of Pathobiology and Population Medicine, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS, United States
| | - Katie Jones
- Department of Pathobiology and Population Medicine, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS, United States
| | - Agne Stoskute
- Group for Reproduction in Animals, Vaccinology and Infectious Diseases (GRAVID™), College of Veterinary Medicine, University of Georgia, Athens, GA 30602-2771, United States
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Midla LT, Hill KL, Van Engen NK, Edmonds M, Renter DG, Streeter MN, Hutcheson JP, Griebel PJ. Innate and acquired immune responses of colostrum-fed neonatal Holstein calves following intranasal vaccination with two commercially available modified-live virus vaccines. J Am Vet Med Assoc 2021; 258:1119-1129. [PMID: 33944597 DOI: 10.2460/javma.258.10.1119] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To compare immune responses induced by 2 commercially available vaccines with a bovine herpesvirus type 1 (BHV1) component following intranasal (IN) administration to colostrum-fed calves. ANIMALS 90 male Holstein calves (ages, 5 to 14 days). PROCEDURES In a randomized complete block design, each calf received 2 mL (1 mL/nostril) of vaccine A (n = 30), vaccine B (30), or saline (0.9% NaCl) solution (30) on day 0. Blood samples were collected for determination of serum anti-BHV1 IgG titer, and nasal fluid (NF) samples were collected for determination of interferon (IFN)-α and IFN-γ concentrations and for secretory IgA titers against BHV1, Mannheimia haemolytica, and Pasteurella multocida at predetermined times for 42 days after vaccination. RESULTS All calves were seropositive for anti-BHV1 IgG, and the mean anti-BHV1 IgG titer did not differ significantly among the 3 groups at any time. Both vaccines induced significant transient increases in NF IFN-α and IFN-γ concentrations. On day 5, mean IFN-α concentration and the proportion of calves with detectable IFN-α concentrations for the vaccine A group were significantly greater than those for the vaccine B and control groups. On day 42, the mean NF anti-P multocida IgA titers for both vaccine groups were significantly greater than that of the control group. CONCLUSIONS AND CLINICAL RELEVANCE Both vaccines induced innate and acquired immune responses in calves with colostral antibodies. The magnitude of the IFN-α response and proportion of calves with detectable IFN-α differed between the 2 vaccine groups. Both vaccines appeared to enhance the IgA response against P multocida.
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Chamorro MF, Palomares RA. Bovine Respiratory Disease Vaccination Against Viral Pathogens: Modified-Live Versus Inactivated Antigen Vaccines, Intranasal Versus Parenteral, What Is the Evidence? Vet Clin North Am Food Anim Pract 2020; 36:461-472. [PMID: 32451035 PMCID: PMC7244452 DOI: 10.1016/j.cvfa.2020.03.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Vaccination of cattle against viral respiratory pathogens to minimize losses associated with bovine respiratory disease (BRD) is a common practice among producers and veterinarians. Three different calf populations in which BRD is most prevalent (recently weaned beef calves, preweaning beef calves, and young dairy calves) are the principal focus of morbidity and mortality prevention through vaccination; however, the evidence of vaccination efficacy is inconsistent in the literature. This review addresses the evidence of efficacy of vaccination in the prevention or reduction of naturally occurring and experimentally induced BRD in each calf group.
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Affiliation(s)
- Manuel F Chamorro
- Department of Clinical Sciences, College of Veterinary Medicine, Auburn University, Large Animal Teaching Hospital, 2020 J.T. Vaughn, Auburn, AL 36849, USA.
| | - Roberto A Palomares
- Department of Population Medicine, College of Veterinary Medicine, University of Georgia, 501 D.W. Brooks Drive, Athens, GA 30602, USA
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