Safety and efficacy of the Novavax vaccine—a narrative review

Abstract

Mass vaccination programs are a public health priority for managing the global coronavirus disease (COVID-19) pandemic. The NVX-CoV2373 vaccine is being developed by Novavax. It consists of a SARS-CoV-2 spike glycoprotein subunit (NVX-CoV2373), which has been shown to have structural stability with pH and temperature perturbations, and the saponin-based Matrix-M adjuvant, which is added to enhance the B- and T-cell-mediated immune response. Animal studies in mice, olive baboons, and cynomolgus macaques demonstrated the potential of this vaccine in protecting the respiratory tract against COVID-19. Subsequent phase 1 and 2 trials then confirmed its safety and the dose-sparing potential of Matrix-M. The results led to the use of a low dose (5 μg) of NVX-CoV2373 in phase 3 trials. In a phase 3 trial involving 14,039 participants, the vaccine efficacy rate was 89.7% (prevention of symptomatic infection). Local and systemic adverse events were mild and self-limiting; commonly reported symptoms included injection-site pain and tenderness, headache, myalgia, and fatigue. A subgroup study confirmed the safety and efficacy of co-administering the NVX-CoV2373 vaccine and the seasonal influenza vaccine. Overall, the vaccine has been found to be safe and effective, meeting the minimum vaccine efficacy rate of 50% to be considered for COVID-19 vaccine emergency use listing approval.

Keywords: Clinical trials, COVID-19, COVID-19 vaccine, immunology