Novavax develops bivalent version of NVX-CoV2373 vac to fend off SA variant

March 6, 2021 0 By FM

Novavax Inc has started developing a new bi-valent version of its COVID-19 vaccine NVX-CoV2373 that could offer protection against the highly mutant B.1.351 variant, first isolated in South Africa, the company said.

NVX-CoV2373 demonstrated 95.6% efficacy against the original strain of the virus and retains 85.6% efficacy against the UK variant (501Y.V1) as per initial interim data from a UK-based phase 3 trial. However, the efficacy level of the protein vaccine candidate dropped to a worrying 60 percent in preventing mild, moderate and severe COVID-19 caused by B.1.351 variant, showed an analysis of data from a phase 2b trial conducted in South Africa.

But the Gaithersburg, Maryland-based biotech firm is confident that its technology and platform will enable the company to rapidly develop new versions of NVX-CoV2373 vaccine against the variant spike proteins.

“A new “bivalent” vaccine could help protect against two different COVID-19 variants – the original or “ancestral” strain and the strain circulating in South Africa, for example,” said a Novavax spokesperson.

Novavax has already begun work to pursue the development of new versions of the protein antigen, she added.

NVX-CoV2373 is made up of two parts: a recombinant protein nanoparticle and an adjuvant (Matrix-M), which serves to boost the immune response. The vaccine delivers a full-length spike protein, and not the genetic instructions for making the protein used in many leading vaccines which are currently in use.

The benefit of the adjuvant, she added, is that it broadens the immune response, enhancing cross-protection among strains.

The adjuvant is therefore more likely to protect against virus drift. It also increases the neutralising antibodies, inducing long-lasting memory B-cells that enhance B-cell and T-cell immunity. Novavax data showed that at six months, the antibody response was in the range of convalescent sera collected 20 days after recovery.

NVX-CoV2373 is currently undergoing a rolling review process for authorisation with several regulatory agencies worldwide, including European Medicines Agency (EMA), US FDA, UK Medicines and Healthcare products Regulatory Agency (MHRA), and Health Canada.

The higher efficacy level of the Novavax vaccine is partly owing to protein technology. This tried-and-tested technology is already widely used in hepatitis B and pertussis vaccines, reports said.

Novavax hopes to have the capacity to produce 2 billion doses of the vaccine this year. In February, the company announced a Memorandum of Understanding (MOU) with Gavi, the Vaccine Alliance, to provide 1.1 billion cumulative doses of NVX-CoV2373.

The vaccine doses will be manufactured and distributed globally by Novavax and Serum Institute of India (SII), the latter under an existing agreement between Gavi and SII.

Novovax licensed NVX-CoV2373 to SII for development and commercialization in India. SII is responsible for securing regulatory approval. The company will soon be initiating a phase 2/3 programme after which it will submit the vaccine for authorization, the spokesperson informed.