Novavax's COVID-Influenza Combo and High-dose COVID Vaccine Show Strong Immune Responses in Phase 2

10 May 2023 | Wednesday | News

Novavax, Inc. (Nasdaq: NVAX), a global company advancing protein-based vaccines with its novel Matrix-M™ adjuvant, today announced that its COVID-Influenza Combination (CIC), stand-alone influenza and high-dose COVID vaccine candidates all showed a reassuring preliminary safety profile as well as comparable reactogenicity to individual Novavax influenza and COVID vaccine candidates or authorized influenza vaccine comparators. Additionally, all three vaccines demonstrated preliminary robust immune responses.
Image Source : Public Domain

Image Source : Public Domain

  • This Phase 2 trial is evaluating three vaccine candidates: COVID-Influenza Combination, stand-alone influenza and high-dose COVID
  • Preliminary topline immune responses for all three vaccine candidates were robust versus authorized comparators
  • For the stand-alone influenza vaccine candidate, HAI responses were 31 to 56% higher for all four influenza strains compared to Fluad®, and were 44 to 89% higher for A strains compared to Fluzone HD®
  • For the COVID-Influenza Combination vaccine candidate, anti-S IgG and neutralization responses achieved levels seen in Phase 3 trial with Novavax's prototype vaccine, with HAI responses generally consistent with Fluad® and Fluzone HD®
  • All three vaccine candidates were well-tolerated and demonstrated a reassuring preliminary safety profile, with reactogenicity comparable to authorized comparators
  • These Phase 2 results support continued development for all three vaccine candidates


The primary endpoint evaluated the safety of different formulations of the CIC vaccine candidate and the quadrivalent influenza vaccine candidate compared to Fluad®* and Fluzone High-Dose Quadrivalent®** (Fluzone HD), as well as a high-dose COVID vaccine candidate in adults aged 50 through 80. All three vaccine candidates contained Novavax's patented Matrix-M adjuvant and showed reassuring preliminary safety profiles and reactogenicity that was comparable to Fluad and Fluzone HD. The reactogenicity profile remained consistent as the adjuvant or antigen dose was increased.

In all groups there were no adverse events (AE) of special interest, no potentially immune mediated medical conditions and no treatment-related serious AEs. Unsolicited AEs occurred in 25% or fewer of any group and were consistent with diagnoses in the older adult population. Local and systemic symptoms were mostly mild and moderate and occurred at rates comparable to Fluad and Fluzone HD.

"The reactogenicity results support our previous observations that this technology is well suited for combination vaccines because large amounts of antigen can be incorporated without impacting tolerability," said Filip Dubovsky President, Research and Development, Novavax. "The immune responses we observed were robust, and the data we have shared today significantly increase the probability of Phase 3 success."

The CIC vaccine candidate achieved both immunoglobulin G (IgG) and neutralizing levels comparable to Novavax's prototype COVID vaccine (NVX-CoV2373). In addition, several of the combination formulations achieved responses to both SARS-CoV-2 and to the four homologous influenza strains that were comparable to the reference comparators, supporting their prioritization for advanced development. The stand-alone influenza vaccine candidate achieved statistically significant hemagglutination inhibition (HAI) antibody responses 31 to 56% higher for all four strains compared to Fluad. Titers were 44 (H1N1) to 89% (H3N2) higher for A strains and statistically non-inferior for B-strains compared to Fluzone HD.

The highest dose stand-alone COVID vaccine candidate achieved statistically significant anti-S IgG and neutralization responses approximately 30% higher than Novavax's prototype COVID vaccine while maintaining comparable safety and reactogenicity to currently authorized dose level of Nuvaxovid.

"Today's positive data are encouraging and further validate the value of our technology platform and its potential to improve global public health," said John C. Jacobs, President and Chief Executive Officer, Novavax. "This is an important milestone in our journey to create additional value and diversify our portfolio of vaccines."

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