Collaborative research between Kansas State University and the J. Craig Venter Institute in Rockville, Maryland has discovered a potentially safer approach to developing a modified live vaccine to prevent swine influenza virus (SIV) infection. Previous research studies have shown that modified live SIV vaccine candidates can be more successful than the traditional inactivated vaccines. However, these candidates were not yet commercialized and employed in the swine industry. A big concern is the safety issue, i.e., the modified live vaccine might regroup with the endemic influenza A viruses to generate more virulent virus in a host.
To avoid this safety risk, the inventors of this patent pending technology showed that it is possible to use modified bat influenza viruses to create the desired immunogenic response in pigs without the potential for it to regroup. The modified bat viruses are weakened in pigs when compared to the wild type swine virus and are immunogenic to produce coagulation inhibition antibodies.
Using synthetic genomics and reverse genetics, the researchers were able to produce two modified bat influenza that had the coding regions from the bat influenza replaced with those of a swine influenza virus (H3N2). In an initial pig study, a group of four-week-old pigs were infected with the respective viruses. All pigs (9/9) infected with one virus showed fever that lasts for 3-4 days whereas both those injected with the Bat-SIV only induced fever in 6 out of 9 infected pigs that lasted for 1-2 days. No fever was seen in the mock-infected group. All three viruses were able to cause lung lesions in all infected pigs. The TX98 virus induced more severe lung lesions than both modified bat viruses. This early pig study demonstrated that these Bat-SIV candidates can infect and replicate in pigs providing the basis for further research in the potential of this platform to provide heterologous protection against multiple swine influenza virus strains. Importantly, the researchers demonstrated no regroup occurred when cells were co-infected with either Bat-SIV candidates and a canonical influenza A virus including a wild-type SIV stain.
- Potentially have all advantages of live attenuated virus vaccines
- Potentially more efficacious than killed vaccines
- Potentially providing heterologous protection against numerous SIV strains
- Demonstrated no reassortment in early studies
- Potentially more safe than available experimental live vaccines
- Rapid adaption to antigenic and genetic changes of influenza viruses
- PCT application was filed in September 2015.