On Sept. 8, 2021, Novavax announced enrollment of the first participants in a Phase 1/2 study to evaluate the safety and immunogenicity of a combination vaccine using Novavax’s seasonal influenza and COVID-19 vaccines. The clinical trial combined Novavax’s recombinant protein-based NVX-CoV2373 and NanoFlu vaccine candidates and patented saponin-based Matrix-M adjuvant in a single formulation (COVID-NanoFlu Combination Vaccine). Both NVX-CoV2373 and NanoFlu previously demonstrated strong results as standalone vaccines in Phase 3 clinical trials.

The trial will evaluate the safety, tolerability and immune response to NanoFlu formulated together with NVX-CoV2373 and Matrix-M adjuvant in 640 healthy adults 50 to 70 years of age. Participants will have been either previously infected with the SARS-CoV-2 virus that causes COVID-19 or vaccinated through an authorized vaccine at least eight weeks prior to enrollment. All participants will be randomly assigned to cohorts to evaluate multiple formulations and will be dosed on Day 0 and again at Day 56. The trial will be conducted in Australia at up to 12 study sites, with results expected during the first half of 2022.

In preclinical studies, the COVID-NanoFlu Combination Vaccine demonstrated robust, functional immune responses to each component of the quadrivalent influenza vaccine and the SARS-CoV-2 spike protein, with Matrix-M adjuvant playing a key role.

In a Phase 3 clinical trial with nearly 30,000 adults in the United States and Mexico, NVX-CoV2373 demonstrated 100% protection against moderate and severe COVID-19 infection and 90.4% efficacy overall. In a pivotal Phase 3 trial conducted among adults aged 65 and older, NanoFlu achieved the primary endpoints, demonstrating non-inferior immunogenicity to a licensed comparator on all four influenza virus strains included in the vaccine, while also showing both enhanced wild-type hemagglutination-inhibiting antibody responses against homologous and multiple heterologous A/H3N2 strains, and potent induction of T cell responses.

NVX-CoV2373 has also been evaluated in a co-administration study where it was administered simultaneously with an approved influenza vaccine. The study demonstrated that vaccine efficacy appeared to be preserved in those receiving both vaccines compared to those vaccinated with NVX-CoV2373 alone.