Researchers in Nebraska believe they are getting closer to an effective and potentially universal vaccine for swine flu. With results of a study published in Frontiers Immunology in May 2023, the scientists from University of Nebraska are now looking forward to larger studies and possible partnerships to accelerate their progress.
Protecting pigs protects people
We know from our conversations with experts in veterinary sciences and animal vaccine development at the Congress in April that vaccines for animals have benefits to human health as well. For a start, food security is affected by animal health. Additionally, pigs are possible “mixing vessels”, claims the University, providing a virus with potential to “reconfigure and become transmissible to humans”.
PhD candidate and lead author of the study, Erika Petro-Turnquist, acknowledged the “significant role” of swine in the “evolution and transmission of potential pandemic strains of influenza”.
“It is imperative that efforts be made toward the development of more effective vaccination strategies in vulnerable pig populations.”
Nebraska Centre for Virology
Petro-Turnquist’s supervisor is Dr Eric Weaver, Director of the Nebraska Centre for Virology. Dr Weaver’s lab specialises in creating a more broad-based vaccine against influenza. This is particularly challenging because of influenza’s rapid mutation patterns. Using Epigraph, a data-based computer technique, the team can analyse “countless” amino acid sequences among hundreds of flu virus variants to create a vaccine comprising the three most common epitopes.
Dr Weaver suggests that their work is like “reversing the evolution” and “bringing these sequences that the immune system recognises as pathogens back together”.
“We’re computationally re-linking them and that’s where the power of this vaccine is coming from, that it provides such good protections against such a wide array of viruses.”
Testing the vaccine
The most recent study is believed to be the first longitudinal study comparing the onset and duration of an adenovirus-vectored vaccine with the performance of a whole inactive virus vaccine. 15 Yorkshire cross-bred female pigs were observed over a period of about 6 months. The group was divided into three groups of 5, the first of which received the Epigraph vaccine. The second group had a commercial whole inactive virus vaccine, and the third group received a saline solution.
Antibody levels and T cell responses were measured weekly during the first month and every 30 days after that. When the pigs reached 6 months of age, they were exposed to a swine flu strain that was not directly represented in the vaccine. The results suggest that the Epigraph-vaccinated pigs had faster and longer-lasting protection from the vaccines against the disease, as well as less viral shedding and fewer symptoms of infection.
Dr Weaver was particularly impressed with the vaccine’s effectiveness over the rate of growth of the pigs: “those pigs weighed about five pounds when we vaccinated them and by the end of the study…they were over 400 pounds.”
“The more times we do these studies, the more confident we get that this vaccine will be successful in the field.”
If this area interests you, why not check out our interviews with Capt. Dr Jennifer McQuiston, Professor James Roth, or Joel Harris, filmed at the Congress in April. Don’t forget to subscribe to get more like this delivered straight to your inbox every week.