Novavax COVID-19 Vaccine Gets Recommended for FDA Emergency Use Authorization

Last week, Novavax announced that it received positive feedback from the US Food and Drug Administration (FDA) Vaccines and Related Biological Products Advisory Committee (VRBPAC) regarding the safety and efficacy of its COVID-9 vaccine (NVX-CoV2373). The unanimous recommendation will be considered by the FDA when deciding whether to approve the vaccine for Emergency Use Authorization in adults 18 years or older. The Novavax COVID-19 vaccine was recommended for emergency use in adults by the World Health Organization (WHO) in December 2021, and is approved in over 40 countries.

The Novavax COVID-19 Vaccine Candidate

The Novavax candidate NVX-CoV2373 is a protein-based vaccine developed using recombinant nanoparticle technology. The vaccine delivers a recombinant version of the SARS-CoV-2 spike

protein that triggers the immune system to generate antibodies against the virus. NVX-CoV2373 also includes an adjuvant called Matrix-M. Adjuvants can help boost the effectiveness of a vaccine and elicit a stronger immune response. If approved, NVX-CoV2373 would become the first available protein-based vaccine against COVID-19 in the US. The vaccine is given in two doses.

Clinical Trial Results

The PREVENT-19 (the PRE-fusion protein subunit Vaccine Efficacy Novavax Trial | COVID-19) trial was a Phase III randomized, placebo-controlled study that evaluated the efficacy, safety and immunogenicity of NVX-CoV2373 with a Matrix-M adjuvant. This trial included nearly 30,000 adults across over 100 sites in the US and Mexico. NVX-CoV2373 was found to be highly effective, with approximately 90 percent protection against COVID-19; it was also well tolerated. The trial was conducted in the first half of 2021, so the vaccine was tested against the original COVID-19 strain (alpha) prior to the emergence of variants. Another Phase III trial conducted in the UK in adults demonstrated approximately 90 percent efficacy against alpha and higher efficacy against other variants.

Results from the PREVENT-19 pediatric expansion trial showed that the vaccine was also effective in adolescents aged 12 to 17 years. The study demonstrated 80 percent efficacy in this population during the time when the delta variant was circulating. Compared to adults, immune responses were approximately two- to three-fold higher in adolescents.

Comparing the Novavax COVID-19 Vaccine to Currently Available COVID-19 Vaccines

In the US, three COVID-19 vaccines from Pfizer-BioNTech, Moderna and Johnson & Johnson (J&J) are available for use. The Pfizer-BioNTech and Moderna vaccines were developed using mRNA technology. These vaccines deliver instructions to make the spike protein using mRNA. The body creates the protein, triggering the production of antibodies against COVID-19 to protect against future exposure to the virus. These vaccines are highly effective, with clinical trial results showing approximately 95 percent effectiveness against the virus; the vaccines are also safe with mostly tolerable side effects. The J&J vaccine was developed using a different vaccine approach in which a harmless cold virus is delivered that carries a genetic code on the spike protein to trigger an immune response. This vaccine is less effective than the mRNA vaccines (approximately 65 to 70 percent) and carries a risk of rare blood clots and other safety concerns. The Pfizer and Moderna vaccines are given in two doses, while the J&J vaccine is given in one dose.

NVX-CoV2373 was found to be as effective as the two mRNA vaccines and more effective than the J&J vaccine. In addition, the trials were conducted later in the pandemic and the vaccine showed efficacy against different variants. NVX-CoV2373 is the only vaccine to use an adjuvant; these have been commonly used for many years to help boost vaccine efficacy. NVX-CoV2373 can be stored up to six months at refrigerator temperatures, which provides an advantage for global distribution. While many people have received their full COVID-19 vaccine doses, if approved, NVX-CoV2373 would provide another option for mixing booster doses and possibly reach people who have not yet had access to the vaccines.

Novavax Vaccine Research

As Novavax waits on FDA approval of NVX-CoV2373 , they are also working on vaccines for the omicron variant, as well as vaccines for seasonal influenza, respiratory syncytial virus (RSV), Middle East Respiratory Syndrome (MERS), Severe Acute Respiratory Syndrome (SARS), malaria and Ebola. These vaccines are being developed using the company’s recombinant, protein-based nanoparticle technology.