Research Terms
This vaccine uses a bacterial vector to deliver multiple Brucella melitensis antigens that should produce enhanced immunogenicity and prevent brucellosis in farm animals. Brucella abortus, melitensis and suis infect cattle (and other large ruminants), sheep and goats, and swine, respectively. Infections are most prevalent in farm animals in the developing world and also in wildlife populations in the developed world. Brucellosis causes abortion and sterility in mammals resulting in substantial economic losses in the livestock industry and is a significant human health problem, especially in the developing world due to consumption of unpasteurized milk and milk products leading to Brucella transmission to humans. Current live attenuated vaccines still cause some disease, are not very effective in preventing abortion, and are unsafe in humans.
Researchers at the University of Florida are developing a highly immunogenic vaccine for brucellosis that should prevent B. melitensis infection but also be safe because it uses specific bacterial proteins rather than the attenuated, or killed bacteria. Additionally, this vaccine can be orally-administered, which will make it easier to use, especially in developing countries.
Orally administered brucellosis vaccine for livestock that prevents B. melitensis infection and induces effective immunity, but is safer than currently available vaccines
Dr. Curtiss’ lab is developing a protective immunity enhanced Salmonella vaccine against Brucella melitensis that overcomes the limitations of current vaccines. The researchers have eliminated Salmonella’s means to suppress and evade induction of acquired immunity while increasing its ability to recruit and stimulate innate immunity to collectively enhance induction of protective immunity. The vaccine vectors display in vivo regulated delayed expression of attenuation and regulated delayed in vivo synthesis of protective antigens. Both attributes enable vaccine vectors at the time of mucosal administration to invade and effectively colonize lymphoid tissues as efficiently as the wild-type parental Salmonella to maximize immune responses to antigens delivered by vaccine vector. Lastly, the vaccine vectors display regulated delayed lysis in vivo to release a bolus of protective antigens. This attribute is a definitive means of attenuation and provides biological containment with no vaccine persistence in vivo or survival if excreted. Scientists have made regulated lysis plasmids encoding 10 different B. melitensis antigens as well as two constructs with fusions of three antigens each. These B. melitensis antigens are more than 95 percent identical in amino acid sequences to the homologous antigens in B. abortus. These vector constructs have been tested in mice.
This developing vaccine against H. pylori bacteria will inhibit infection and reduce incidence of gastric ulcers and stomach cancer. This will be the first effective vaccine for use against H. pylori. In addition, the vaccine will be administered orally.
Researchers at the University of Florida are developing a vaccine against infection by the bacterium Helicobacter pylori, a leading cause of stomach cancer, peptic ulcer disease, and stomach inflammation in humans. H. pylori infection of the stomach is found in about half of people worldwide and is responsible for 60 percent of stomach cancer cases . Currently, no effective vaccine against H. pylori is available and antibiotic treatment for gastric ulcers is often ineffective due to the increasing incidence of antibiotic resistance.
Therapeutic, orally administered vaccine against H. pylori infection, a leading cause of gastric ulcers and stomach cancer in humans
The orally administered vaccine employs an attenuated Salmonella strain as a vector that expresses H. pylori surface antigens to induce mucosal, cellular, and systemic immunity against the bacterium. The vaccine preferentially induces an immune response on mucosal surfaces such as the lining of the stomach, which H. pylori colonizes. Injectable vaccines are not able to induce such mucosal immunity, making this orally administered vaccine a more effective alternative for preventing and perhaps treating H. pylori infection. Although not yet tested in human subjects, oral delivery of this vaccine to mice conferred protection against H. pylori infection.
This recombinant attenuated bacterial vaccine vector is the first live, attenuated bacterial vector developed specifically for use in fish raised in aquaculture systems. This technology enables vaccination against common diseases that afflict fish raised in aquaculture systems by immersion rather than injection. Currently, the most commonly used method for immunization in the aquaculture industry is intraelomicperitoneal injection, which is expensive, labor-intensive and stresses the fish. Clearly, the industry needs improved vaccines because infectious disease agents easily spread between individual fish grown in high density aquaculture systems. The economic losses due to disease morbidity and mortality in the aquaculture industry is approximately $3 billion annually.
Researchers at the University of Florida have developed a live, fully-attenuated bacterial vaccine that can be administered by bath immersion. This vaccine vector system can be effectively used with multiple different fish species and can be used to create multivalent vaccines.
A recombinant fully attenuated Edwardsiella bacterial vector that can be used to immunize a wide variety of fish species against common diseases associated with aquaculture, including septicemia and white spot disease
This vaccine platform is based on a recombinant, fully-attenuated Edwardsiella bacterial vector that was chosen as the delivery vehicle because it efficiently attaches to and invades mucosal, gut, skin and gill associated lymphoid tissue in a wide variety of both fresh and saltwater fish species – including catfish, trout, salmon and tilapia. This then allows fish to be vaccinated by immersing them in a bath containing the bacterial vector. Proof-of-concept has been demonstrated using the vector to express an antigen from the protozoan parasite Ichthyophthirius multifilis. However, the attenuated Edwardsiella bacterial vector also can be used to express antigens that will provide protection against other fish pathogens and multiple antigens can be expressed in the same vector allowing for multivalent vaccines.