Novavax has announced positive preclinical results for its virus-like particle (VLP) caccine candidate against A (H7N9) influenza.
The study examined the immunogenicity, the ability to provoke an immune response, and efficacy of two doses of its A(H7N9) VLP vaccine candidate against a lethal wild-type challenge mouse model.
There were three control groups, including Novavax’ non-homologous A(H7N3) VLP vaccine candidate, its A(H5N1) VLP vaccine candidate, and a placebo. All vaccine candidates were administered with or without Iscomatrix, a saponin-based adjuvant.
Novavax also reported a survival rate of 100%.
The trial, which started only 28 days after the recent A/Anhui/1/13-like H7N9 strain was sequenced, demonstrates complete protection by theA(H7N9) and A(H7N3) VLP vaccine candidates in a lethal live H7N9, explained Novavax’s chief medical officer Dr Gregory Glenn.
"The study showed complete cross-protection when the VLP vaccine was not a perfect match for the challenge virus," said Glenn.
"These animal data add to our confidence that the vaccine candidate will elicit protective immune responses in humans."
VLPs are self-assembling protein structures that resemble the external structure of viruses, elicit broad and strong antibody and cellular immune responses, but lack the live genetic material that causes viral replication and infection.
VLPs contain three of the major structural virus proteins that are important for fighting influenza: hemagglutinin and neuraminidase, both stimulate the body to produce antibodies that neutralise the influenza virus and prevent its spread through the cells in the respiratory tract.
Glenn added that the company is now focused on expanding the campaign. The clinical trial results are published in the online journal Vaccine.
Image: Influenza A (H7N9) as viewed through an electron microscope. Both filaments and spheres are observed. Photo: courtesy of Cynthia S Goldsmith and Thomas Rowe.