Submitted to: Expert Review of Vaccines
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/3/2005
Publication Date: 12/20/2005
Citation: Olsen, S.C., Stoffregen, W.C. 2005. The essential role of vaccines in brucellosis control and eradication programs for livestock. Expert Review of Vaccines. 4(6):915-928. Interpretive Summary: Brucellosis, a disease characterized by abortion and fetal losses, remains endemic in domestic livestock in many areas worldwide. Infection of livestock with B. abortus, B. melitensis, or B. suis pose a significant health risk for transmission to humans by direct contact or from consumption of unpasturized milk products. Infection of humans with Brucella causes a wide range of clinical symptoms including the classical syndrome of "undulant fever". Despite decades of research on brucellosis in livestock, the most efficacious vaccines that are currently available are composed of live bacteria which can cause abortions in pregnant livestock and pose a risk for human infection. In some species, including nontraditional livestock and some wildlife reservoirs, current vaccines are not safe and efficacious, or cause adverse consequences such as making animals test positive on brucellosis surveillance tests. Based on new advances in technology, areas of research are identified which should be assist in the development of improved vaccines that will facilitate reduction or eradication of brucellosis.
Technical Abstract: Brucellosis, in particular infections with B. abortus, B. melitensis, or B. suis, remains a significant human health threat in many areas of the world. The persistence of pathogenic Brucella spp. in domestic livestock, or free-ranging wildlife, remains unresolved despite decades of regulatory efforts worldwide. Although vaccination is probably the most economic control measure, administration of currently available vaccines alone is not sufficient for elimination of brucellosis in any host species. Complacency in brucellosis control programs usually results in failure, or at best, limited reductions in disease prevalence or incidence of human infections. New brucellosis vaccines with high efficacy and safety are needed which address the diversity in host species and can be more widely applied under field conditions. Development of safer and more efficacious vaccines alone, or combined with enhancements or increased emphasis on other regulatory program components, could have tremendous impact on reducing the worldwide prevalence of brucellosis and the associated zoonotic infections.