Topline results from Novavax’s phase 3 Boosting Trial for the SARS-CoV-2 rS Variant Vaccines (COVID-19) found that the company’s BA.1 vaccine candidate (NVX-CoV2515) met the primary strain-change endpoint.

Further, the data show that the neutralizing responses produced by the BA.1 vaccine neutralizing responses were greater than those of the prototype (NVX-CoV2373) among individuals not previously exposed to COVID-19, which enables a shift to a new variant vaccine if necessary, according to Novavax.

"[The] results show that use of our prototype vaccine as a booster induces cross-reactive responses to a broad range of variants with the potential to protect against future strains. This is a hallmark of our vaccine technology and shows the suitability of our current prototype vaccine as a booster even as the COVID-19 landscape continues to evolve," said Gregory M. Glenn, MD, president of Research and Development, Novavax, in a press release. "Our vaccine, which provides broad immune response even in the face of evolving variants, presents a potential strategy to protect against COVID-19 now and into the future."

NVX-CoV2373 is a protein-based vaccine developed from the genetic sequence of the first strain of SARS-CoV-2. The vaccine was created using Novavax’s recombinant nanoparticle technology to produce antigens derived from the COVID-19 spike protein.

The vaccine is formulated with Novavax’s patented saponin-based Matrix-M adjuvant to enhance the immune response and stimulate high levels of neutralizing antibodies. NVX-CoV2373 contains purified protein antigen and can neither replicate nor cause COVID-19.

Further, the vaccine is packaged as a ready-to-use liquid formulation in a vial containing 10 doses, with two 0.5 ml doses administered intramuscularly 21 days apart. The data show no benefit for the Novavax bivalent vaccine candidate compared to the BA.1 vaccine candidate or prototype vaccine in the overall trial population.

The immunoglobulin G (IgG) antibody responses were similar against BA.1 and prototype strains across the 3 vaccine groups (prototype [n=273], BA.1 vaccine candidate [n=279], and bivalent – prototype + BA.1 vaccine candidate [n=277]).

For the BA.5 strain, pseudoneutralization responses found that there was no benefit for the BA.1 or bivalent vaccine candidates compared to the prototype vaccine.

The data demonstrated that the prototype vaccine induced a broad immune response against the original prototype, BA.1 and BA.5 strains. The vaccine produced robust IgG responses to both BA.1 and the matched prototype strain. Additionally, pseudoneutralization responses against BA.5 for the prototype vaccine were comparable to those induced by the

more closely matched BA.1 vaccine and bivalent vaccine candidates.

All 3 vaccine formulations were similarly well-tolerated when given as a second booster dose (fourth dose), which was consistent with the well-established safety profile of the prototype vaccine. The most common local solicited symptom was pain/tenderness, and the most common systemic solicited symptoms were fatigue and malaise, muscle pain, and joint pain, with most reactions being mild or moderate.

REFERENCE

Novavax Phase 3 COVID-19 Omicron Trial Supports the Continued and Future Use of Novavax Prototype Vaccine as a Booster. Novavax. November 8, 2022. Accessed November 8, 2022. https://ir.novavax.com/2022-11-08-Novavax-Phase-3-COVID-19-Omicron-Trial-Supports-the-Continued-and-Future-Use-of-Novavax-Prototype-Vaccine-as-a-Booster