New Peptide Vaccine for Universal Influenza Protection
New approach targets multiple strains, promising broad protection against human, avian, and swine influenza viruses.
A novel, unconjugated single composite peptide vaccine has been created to address the risk of influenza pandemics posed by reassortant strains that incorporate genes from human, avian, and swine origins. The vaccine introduced at IDWeek 2024, addresses the need for a universal vaccine, underscored by the ongoing global threat of highly pathogenic avian influenza (HPAI) A/H5N1 in poultry. This study builds upon previous research that demonstrated the effectiveness of a two-peptide vaccine by introducing a single peptide approach, which simplifies formulation and scalability.
The unconjugated single composite peptide vaccine, containing highly conserved epitopes from hemagglutinin (HA), neuraminidase (NA), and matrix proteins, and formulated with the ALFQ adjuvant, successfully generated broadly reactive antibodies against human, avian, and swine influenza strains, effectively neutralizing both seasonal and pandemic variants. This strategy offers a cost-effective and easily scalable solution for developing a universal influenza vaccine to mitigate future pandemics.
The vaccine induced strong serum IgG1 antibodies against human and avian influenza A and B viruses. Serum collected after immunization exhibited effective neutralization and inhibition of hemagglutination in Group 1 and Group 2 influenza viruses.
Jeff Fischer, MBA, co-founder and president of Longhorn Vaccines and Diagnostics, highlighted the strategies for translating their universal influenza vaccine from mouse models to human clinical trials. The vaccine targets multiple viral components—hemagglutinin (HA), neuraminidase (NA), and matrix proteins (M1/M2/M2e)—to ensure broad coverage against various strains. Fischer emphasized, “Well, I think one thing we've shown in this poster, as well as throughout the presentations that we've given in the past, is we get very, very broad binding and activity against strains across all different types of influenza, whether it be an H1N1, whether it be an H5N1, whether it be an H3N2.”
The vaccine includes highly conserved epitopes along with a universal T cell epitope, formulated with the potent adjuvant Army Liposomal Formulation with QS21 (ALFQ). In preclinical trials, ICR mice received intramuscular immunizations of the vaccine, resulting in strong serum IgG1 responses to both human and avian influenza A and B viruses. The post-immunization sera demonstrated effective neutralization and inhibition of hemagglutination in Group 1 and 2 influenza viruses.
Fischer further elaborated on the advantages of the single composite peptide approach, stating, “Well, we think the opportunity to deliver all of these different components has been something that's been challenging in the past. By using this approach, we can put them all together into a single vaccine. We can also change the order by which they're placed, so that it's set up to optimally deliver the epitopes to the body, allowing the body to respond with its normal immune response and generate a long-term immune response.”
Looking ahead, Fischer shared their plans to evaluate the vaccine as a mucosal vaccine for intranasal administration. “We're really excited about the next stage, which is that we want to look at this as a mucosal vaccine. The next step, and what we're preparing to do, and should have data on very soon, is looking at this intranasally. We believe that if we can create that mucosal immunity, we can prevent these infections entirely or significantly reduce them,” he said. “So that we're not just trying to reduce how sick you are or how long you're sick, but maybe keep people from getting sick at all.”
