Brucellosis Vaccine For Cattle

Vaccination is a determinant strategy for brucellosis control and eradication programs, therefore it has been the target of innumerous studies over decades. Nowadays, some effective vaccines are available to control the disease in cattle. S19 and RB51 are the officially approved B. abortus vaccine strains more widely and successfully used to prevent bovine brucellosis worldwide. However, due to some side effects shown by these current vaccines, plus the advances in recombinant DNA technology and the lack of a vaccine for humans, there is an on going extensive efforts focused on the development of new and better vaccines. Engineered vaccines have the potential to be the future of the bovine and human brucellosis control, but many studies are still needed to develop a better vaccine than the current vaccines in terms of safety, efficacy and other desirable characteristics.

Moreover, it is important to consider that, mainly non-living recombinant vaccines, also present important issues, as the requirement of multiple boosters, adjuvants, and optimal combination of antigens, besides usually inducing poor cellular immune response. In addition, although the excellent results observed for some recombinant vaccines in mice, very few of these candidate vaccines have been evaluated in cattle. The recent studies indicate that the future of a new B. abortus vaccine will be the construction of directed mutants, which exclude the drawbacks and simultaneously increase immunogenic characteristics presented by S19 and RB51. Furthermore, concerning the immune response induced after S19 and RB51 vaccination in cattle, as well as after RB51 revaccination, very little is understood. Efforts to find out the principal characteristics of the immune response triggered in cattle by the two most used and successful B. abortus vaccine strains are essential to try to establish an ideal vaccine. The definition of immune markers correlated with protection, by mathematical modeling or evaluation of the immune response in vaccine – challenge studies – would be very helpful in the screening of B. abortus candidate vaccines.

Description

Brucella abortus is a bacterium that causes brucellosis in cattle. B. abortus RB51 is a strain of this bacterium developed specifically for immunization of cattle against brucellosis to allow serological differentiation between naturally infected and vaccinated animals. Accidental human exposure to RB51, though uncommon, has resulted in development of symptoms consistent with brucellosis. Exposures have included needle sticks, eye and wound splashes, and contact with infected material.

Other vaccines, such as Brucella abortus S19 for cattle and B. melitensis Rev-1 for sheep and goats, can also cause infection in humans. Veterinarians and other medical staff performing immunizations in cattle should be aware of the risks and what to do when an exposure occurs. S19 and Rev-1 exposures should follow the same assessment guidance as for RB51. Serological monitoring is available for S19 and Rev-1 exposures.

Features of Brucellosis Vaccine For Cattle

Attenuated B. abortus strains have demonstrated the best results in the prevention of bovine brucellosis, probably because these vaccines are able to multiply within animals for a short period of time and thereby induce a strong and protective cellular immune response. Massive vaccination against brucellosis in cattle have been performed employing few vaccine strains, S19, RB51, 45/20 and SR82, although many B. abortus vaccine candidates have been developed over the last years, such as DNA, subunit, recombinant B. abortus and recombinant vector vaccines

The 45/20 was a bacterin used in some European countries, but the variability in reported protection, along with unpredictable serological effects and the occurrence of reactions at the site of vaccine injection in some animals led to the interruption of the use of this vaccine . The SR82 strain is a live attenuated vaccine used since 1974 by the former Union of Soviet Socialist Republics (USSR) for bovine brucellosis control. Currently, the SR82 strain is still massively used in the Russian Federation, Azerbaijan, Tajikistan and other countries in the region Recombinant vaccines are part of the continuous efforts to reach a safer and more effective B. abortus vaccine, with the potential to be the future of cattle and human brucellosis control. However, many studies are still needed to achieve the ideal vaccine against brucellosis. The majority of these genetically engineered vaccines was developed and tested using mouse models and they have not been tested or were not protective in cattle Among the live modified B. abortus vaccines, S19 and RB51, are the most widely used strains around the world.

Benefits of Brucellosis Vaccine For Cattle

Most of our knowledge on the protective response induced by both widely used B. abortus vaccines, S19 and RB51, comes from studies using mice. In murine models, a Th1 cellular immune response with production of IFN-γ, mainly by CD4+ T-cells and CD8+ specific cytotoxic cells, but not IL-4, have been demonstrated as the main response following RB51 vaccination ]. Likewise, following S19 vaccination, mice exhibited a strong Th1 immune response with production of IL-2, TNF-a and IFN-γ, and high levels of antigenspecific CD4+ and granzyme B-secreting CD8+ T-cell responses, but not IL-4 or IL-10 secretion .

Prices of Brucellosis Vaccine For Cattle

$35.00-$90.00

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