Research Spotlight: Combinatorial Liposomal Peptide Vaccine Induces IgA and Confers Protection Against Influenza Virus and Bacterial Super-Infection

Posted on November 12, 2021

3 D Phad Article Image

3D-PHAD… sounds cool, right? Well, there’s more to this Avanti Lipid product than a cool name. Avanti’s PHAD is the first fully synthetic monophosphoryl lipid A (MPLA) available for use in human vaccines. But what does the 3D stand for? 3D means that this PHAD product is a 3-deacylated form of MPLA. Avanti’s PHAD products are great adjuvants for human vaccine applications due to their ability to elicit a strong immune response while also exhibiting a lower pyrogenic profile than the naturally occurring bacterial agent. Enough about this product’s name, let’s look at how it’s being used!

The Problem

Influenza virus is a common pathogen that causes annual outbreaks and epidemics during winter months across the world. Many deaths associated with the flu are caused by a secondary bacterial pathogen, Streptococcus pyogenes. So, there is great demand for a vaccine that can combat both pathogens.

Each year, the prevalent flu strain(s) changes. That is why the flu vaccine is not always extremely effective and why they are updated every single year. The vaccine must be altered to cover the strains that might be most prevalent in an upcoming flu season. And streptococcus vaccines currently being investigated are limited in some areas depending on the area’s diversity of the pathogen. So, how do we develop a vaccine that can control both pathogens effectively and without the need for alterations every year?

The Current Strategy Being Investigated to Answer this Question

The transmembrane ion channel M2 protein is a promising vaccine target for influenza. This is due to the entire M2 protein ectodomain being highly conserved among human influenza viruses. A promising streptococcus vaccine approach focuses on the induction of antibodies to a conserved M-protein epitope called J8. Streptococcus vaccines containing the J8 epitope attached to a fatty acid tail have been proven to induce IgA when administered intranasally. And that is how researchers at the University of South Dakota and Griffith University in Queensland, Australia plan to combat these pathogens with a single vaccine. Studies have shown that both influenza and streptococcus pathogens have something in common: immune responses to each of these pathogens relies on a common, critical antibody, IgA.

They were able to prove that, at least in animal models, a liposomal vaccine adjuvanted with 3D-PHAD expressing both peptide epitopes can protect against both pathogens simultaneously. Separately, these epitopes had previously been shown to protect against multiple strains of influenza virus and streptococcus, but this is the first time that a combined epitope vaccine has shown efficient and equivalent induced immunity against both a viral and bacterial pathogen. The researchers went on to say that this liposomal vaccine will likely not become a substitute for the common influenza vaccine, but rather that this research serves as a basis for future work creating broadly effective flu vaccines combined with other antigens.

We are proud to provide lipids that made this work possible, and we want to thank the research groups from Griffith University and the University of South Dakota for trusting Avanti’s lipid products in their research! The liposomes were formulated with DPPC, cholesterol, and PG and adjuvanted with 3D-PHAD, all from Avanti.

Are you interested in conducting your own adjuvanted vaccine research? Your research deserves the high-quality lipids that only Avanti can provide.

Click HERE to read the full research article!

Image Credit: Original Research Publication