CategorySwine Health-Foreign Animal Disease
Date Full Report Received01/30/2015
Date Abstract Report Received01/30/2015
Funded ByNational Pork Board
The African Swine Fever Virus is a high-consequence pathogen that causes hemorrhagic fever in pigs and some isolates are capable of killing nearly all infected pigs. The pathogen poses a high risk to the USA swine industry as it continues to spread globally and therefore, it is important that innovative products are developed to safeguard the industry. There is no vaccine or treatment available for controlling this disease and therefore, development of an effective and safe vaccine is necessary for use in case there is an outbreak in North America. The overall goal of this project is to develop a vaccine for protection of pigs against the virus. To achieve this goal, the initial steps require identification of virus proteins that can confer protection, formulation of a candidate vaccine, and evaluation of the ability of the vaccine to safely induce protection in commercial pigs. In this project, we generated a rationally designed vaccine containing candidate proteins from the virus and tested the ability of the vaccine to safely stimulate antibody and T cell responses in commercial pigs.
There is scientific evidence to show that protection against the African swine fever virus can be stimulated with a vaccine since pigs that recover from infection with isolates that do not cause disease are protected against related isolates that cause disease. Due to safety concerns, development of a vaccine based on carefully selected virus proteins, as opposed to an attenuated live virus vaccine, is more attractive for use in U.S.A since the virus is not present in North America. However, the current challenges are identification of suitable virus vaccine candidate proteins and an effective way for immunizing pigs. Candidate vaccines formulated using one or two African swine fever virus proteins have so far failed to induce acceptable protection. It is envisaged that development of an effective vaccine will require identification and validation of multiple suitable candidate proteins that will induce significant protection in majority of the vaccinated pigs.
We developed a vaccine candidate containing multiple promising African swine fever virus proteins and immunization of commercial piglets with the vaccine induced strong antibody and T cell responses that increased over a ten week period after immunization. Overall, the vaccine was well tolerated and no serious negative effects were observed. Notably, all the piglets responded well to each virus protein in the vaccine. In addition, the induced responses increased dramatically upon boosting. More importantly, the induced antibodies strongly recognized the actual African swine fever virus. Taken together, the outcomes from this study showed that the vaccine is capable of safely inducing strong immune responses in commercial pigs. The next logical step is to test whether the vaccine can confer protection against the virus.
Dr. Waithaka Mwangi
Dept. of Veterinary Pathobiology
College of Veterinary Medicine & Biomedical Sciences
Texas A&M University