Dr. Zakia Goodwin and Dr. David Pascual look at data used in their study of a new vaccine prototype aimed at protecting small ruminants from a devastating strain of brucellosis.
A novel vaccine, developed by University of Florida researchers for use against a devastating strain of brucellosis that affects small ruminants, has shown groundbreaking effectiveness in conferring long-term immunity in mice.
David Pascual, Ph.D., a professor of infectious diseases at UF’s College of Veterinary Medicine, and his colleagues demonstrated the vaccine’s ability to generate a robust population of disease-fighting T cells in the lungs and spleen that helped to control systemic infection, they reported recently in Frontiers in Immunology.
“Although brucellosis is not a new disease and is believed to have existed since the domestication of livestock, the lack of effective vaccines has renewed efforts to develop more effective animal vaccines as well as human vaccines,” Pascual said, adding that live, attenuated brucellosis vaccines are used for livestock, but not for humans.
Now classified by the U.S. Centers for Disease Control and Prevention as a re-emerging pathogen, brucellosis continues to impact developing countries and persists in expanding populations of wildlife species in the United States, constantly threatening domestic herds with infection.
In the U.S., brucellosis persists in bison herds in Yellowstone, which can infect domestic livestock upon contact, resulting in lost pregnancy in infected cows. Elsewhere in the country, the disease is typically introduced into bovine herds by exploding populations of feral pigs. Worldwide, Brucella melitensis strain infects small ruminants with increased prevalence in recent years, due to multiple factors, including expansion of wildlife species. Humans are at risk of infection from consuming unpasteurized goat milk and cheeses, and infection can lead to rising and falling fevers, sweats, malaise and weakness, among other symptoms if left untreated.
The new live, attenuated mucosal vaccine was tested using an oral delivery method followed by an intranasal boost — an approach few studies have investigated. Vaccines currently used against this strain of brucellosis are injected under the skin. This method does not target the disease’s primary infection route, which is through the mouth and nose, the researchers said.
Dr. Zakia Goodwin, who completed her Ph.D. at the UF College of Veterinary Medicine in 2022, stands with her mentor, Dr. David Pascual.
“Other vaccines currently used to protect again against Brucella melitensis are not ideal,” said Zakia Goodwin, D.V.M., Ph.D., a study co-author. “If your goal is disease eradication from a population, surveillance through testing is important to identify diseased animals. With some existing vaccines, it is difficult to distinguish naturally infected from vaccinated animals. This vaccine addresses this challenge and also provides equal or better protection as the others.”
The study was part of Goodwin’s doctoral research program at UF.
