Novavax's vaccine was tested in three animal models, including the ferret, which is the most predictive model for influenza vaccine effectiveness in humans. Protection, as measured by a reduction in viral load, was assessed in vaccinated ferrets challenged with live H9N2 avian influenza.
Virus-like particles mimic the three-dimensional structure of a virus but do not contain genetic material, so they cannot replicate or cause infection. As VLPs maintain functional properties of both influenza surface proteins, they likely trigger multiple arms of the immune system to generate a broadly protective immune response.
Novavax has conducted several preclinical studies evaluating a number of its VLP vaccines against different strains of avian influenza.
As part of the study, Novavax also evaluated its proprietary Novasome adjuvant with both the H9N2 VLP vaccine and a recombinant hemagglutanin antigen vaccine. Both vaccines combined with adjuvant were shown to provide protection in mice. Adjuvants are used to improve the efficacy of vaccines and may help reduce the dosage required for protection in a pandemic setting.