Vaccination and immune response of cattle against the bovine viral diarrhoea
-
1
Universidad Nacional de Rio Negro, Microbiology, Argentina
-
2
Universidad Nacional del Centro, Animal Health, Argentina
Bovine Virus Diarrhoea (BVD) is a serious cattle disease and readily establishes endemic infections in cattle populations. After maternal infection, some non-cytopathic BVD viruses can cross the bovine placenta and infects the conceptus. This leads to transient reproductive problems, abortion, generating persistent infected animals, and stillbirths. In contrast, most postnatal infections run only a very mild course. Therefore the primary aim of vaccination is to prevent congenital infections .Vaccination to prevent severe postnatal infections may be indicated only when virulent BVDV strains are prevalent. BVD vaccines are most effective in preventing the acute disease, but their benefit is doubtful as far as foetal protection and prevention of fertility disorders is concerned
Different strategies to control infection by the bovine viral diarrhoea virus (BVDV) within a herd can be carried out to farmers: either protection by vaccination, or strategies combining monitoring, screening and elimination of persistently Infected (PI) animals) with biosecurity. The use of vaccines to protect against the disease and/or to reduce the level of infection within the population has been the cornerstone of preventive medicine for over a century.
Some vaccines have published data of good efficacy both experimentally and in the field. The selection and proper use of such BVDV vaccines should ensure the foetal protection against circulating viruses. Modified live vaccines contain cytophatic (cp) BVDV. This means, the vaccine is unable to produce PI animals. However, modified live vaccines have been known to trigger Mucosal Disease in PI animals. Hence, vaccinating PI animals is not only useless, it’s even risky.
Modified live vaccines may have a similar immunosuppressive effect as their respective field strains. This means a higher susceptibility to other pathogens or a possible aggravation of an existing medical condition.
Vaccination with killed vaccines results in serum antibodies directed mainly at the E2 protein, with the major neutralizing epitopes are conformational and are located within the N-terminal half of the E2 protein. Prevention of foetal infections requires T and B cell response levels that approach immunity.
The aim of our work was evaluated the serological status and viral dynamics on vaccinated /non vaccinated herds, with or without clinical BVDV stories. Only killed vaccines are authorized in our country. Blood sera samples from 229 animals of three herds were tested to detect BVDV antibodies and BVDV antigens in peripheral blood leukocytes (PBL) samples for by ELISA methods.
Lysed PBL from 36 seropositive animals showed BVDV antigens in ELISA test, while the virus could not be detected in 193 seropositive cattle . Wild type BVDV strains were isolated by co culture on polycation treated MDBK cells from 11 of these virus harboring animals.
The first dairy herd, without clinical signs or vaccinations against BVDV, no presented PI animal, but a 16,65 % of seropositive cattle was BVDV carrier, while the 83.34% of seropositive animals was viral free.
A second non vaccinated dairy herd was selected, showed BVDV seropositive status and many clinical signs. The samples were from 136 females of ages ranging from 6 to 36 months. In this group, 6.2% of seropositive cattle showed BVDV activity.
At the third herd, from beef industry, 45 seropositive animals were analyzed. These animals were vaccinated and showed clinical and serological evidence and viral activity of the BVDV. I this group, we detected a PI animal, while 19 % of seropositive cattle was BVDV carrier and the 81 % of seropositive animals was viral free. The detection of BVD virus in a blood sample of a 4 month old clinical healthy calf routinely tested was therefore unexpected.
The circulating antibodies of these seropositive carrier animals were able to neutralize their autologous virus strain, indicating that virus may persist in the spite of the presence of strain specific antibodies. The heterogeneity that exists among circulating BVDV strains, works against establishing such immunity.
A BVD vaccine is supposed to protect an individual from disease as well as to protect a foetus from intrauterine infection and prevent fertility problems. Protection from disease is good these days with modern vaccines, however foetal protection is not complete and neither is protection against reduced fertility.
Killed vaccines are safer to use than live vaccines. However, they tend to be substantially less effective than live vaccines and require frequent boosters (twice a year minimum).
Although not 100% effective in every individual animal, vaccination was effective at the herd level. No gross immune malfunction could be detected in any category of virus positive animals. We concluded that BVDV virus may be persistently harbored in cattle, albeit with different capabilities, in spite of a specific active immune response.
It is also still concern that vaccine-induced antibodies may interfere with diagnostic serology. For this reason, there is a future need for efficacious, broad spectrum and safe ‘marker’ vaccines.
Keywords:
bovine,
Bovine viral diarrhoea,
Vaccines,
seropositive animal,
seropositive carriers
Conference:
IMMUNOCOLOMBIA2015 - 11th Congress of the Latin American Association of Immunology - 10o. Congreso de la Asociación Colombiana de Alergia, Asma e Inmunología, Medellin, Colombia, 13 Oct - 16 Oct, 2015.
Presentation Type:
Poster Presentation
Topic:
Veterinary and Comparative Immunology
Citation:
Gogorza
LM and
Morán
PE
(2015). Vaccination and immune response of cattle against the bovine viral diarrhoea.
Front. Immunol.
Conference Abstract:
IMMUNOCOLOMBIA2015 - 11th Congress of the Latin American Association of Immunology - 10o. Congreso de la Asociación Colombiana de Alergia, Asma e Inmunología.
doi: 10.3389/conf.fimmu.2015.05.00234
Copyright:
The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers.
They are made available through the Frontiers publishing platform as a service to conference organizers and presenters.
The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated.
Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed.
For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions.
Received:
15 May 2015;
Published Online:
14 Sep 2015.
*
Correspondence:
Dr. Lidia M Gogorza, Universidad Nacional de Rio Negro, Microbiology, Choele Choel, Río Negro, 8360, Argentina, lgogorza@vet.unicen.edu.ar