‘Hexaplex’ Vaccine Aims to Boost Flu Protection

Recombinant protein vaccines, like the Novavax vaccine used to fight COVID-19, offer several advantages over conventional vaccines. They’re easy to precisely produce. They’re safe, and potentially more effective. And they could require smaller doses.

Because of these traits, there is much interest in developing recombinant influenza vaccines. To date, however, the Food and Drug Administration has approved only one such vaccine.

A University at Bufalo-led research team hopes to add to that number. It is developing a new recombinant flu vaccine — described in a study published today in the journal Cell Reports Medicine — that has the potential to compete with existing vaccines.

Conventional flu vaccines contain either deactivated microbes that cause influenza, or they are based on weakened forms of the disease. They are made using fertilized chicken eggs or, less commonly, through cell culture-based production.

The vaccine the UB-led team is developing is based on a nanoliposome — a tiny spherical sac — that Lovell and colleagues created called cobalt-porphyrin-phospholipid, or CoPoP. The CoPoP platform enables immune response promoting proteins to be displayed on the surface of the nanoliposome, resulting in potent vaccine efficacy.

In the new study, the team attached to the nanoliposome a total of six proteins — three each from two different protein groups, hemagglutinins and neuraminidases. The team also added two adjuvants (PHAD and QS21) to boost immune response.

Researchers evaluated the resulting “hexaplex” nanoliposome in animal models with three common flu strains: H1N1, H3N2 and type B.

Even when administered in low doses, the hexaplex nanoliposome provided superior protection and survival from H1 and N1 when compared to Flublok, which is the sole licensed recombinant influenza vaccine in the U.S., and Fluaid, an egg-based vaccine. Tests showed comparable levels of protection against H3N2 and type B viruses.

The tests were performed via vaccination and through blood serum transfer from vaccinated mice into non-vaccinated mice.


Zachary R. Sia, Jayishnu Roy, Wei-Chiao Huang, Yiting Song, Shiqi Zhou, Yuan Luo, Qinzhe Li, Dominic Arpin, Hilliard L. Kutscher, Joaquin Ortega, Bruce A. Davidson, Jonathan F. Lovell. Adjuvanted nanoliposomes displaying six hemagglutinins and neuraminidases as an influenza virus vaccine. Cell Reports Medicine, 2024; 101433 DOI: 10.1016/j.xcrm.2024.101433

University at Buffalo. (2024, February 26). ‘Hexaplex’ vaccine aims to boost flu protection. ScienceDaily. Retrieved February 28, 2024 from www.sciencedaily.com/releases/2024/02/240226114654.htm

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