PRE-CLINICAL IMMUNE RESPONSE AND SAFETY EVALUATION OF THE PROTEIN SUBUNIT VACCINE NANOCOVAX FOR COVID-19

Mai, Tran Thi Nhu; May, Bruce; Thuan, Ung Trong; Khoi, Nguyen Mai; Trang, Nguyen Thi Thuy; Van Long, Dinh; Chung, Doan Chinh; Vinh, Tran The; Hiep, Khong; Truc, Nguyen Thi Thanh; Huy, Hua Hoang Quoc; Anh, Nguyen Viet; Phat, Ha Tan; Luu, Phan Dang; An, Nguyen Truong; Ngoc, Bui Thi; My, Tu Tieu; Theo, Nguyen Thi; Hang, Le Thi Thuy; Lan, Dong Thi; Hieu, Huynh Trong; Huong, Ho Phien; Thao, Le Nguyen Thanh; Thao, Truong Cong; Phi, Pham Hoang; Luong Cong, Y; Lim, Nie; Ngoc, Cao Minh; Khanh, Nguyen Duy; Hung, Trinh Thanh; Si, Do Minh

The Coronavirus disease-2019 (COVID-19) pandemic caused by the Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2), has become a dire global health concern. The development of vaccines with high immunogenicity and safety is crucial for control of the global COVID-19 pandemic and prevention of further illness and fatalities. Here, we report development of SARS-CoV-2 vaccine candidate, Nanocovax, based on recombinant protein production of the extracellular (soluble) portion of the S protein of SARS-CoV-2. The results showed that Nanocovax induced high levels of S protein-specific IgG, as well neutralizing antibody in three animal models including Balb/C mice, Syrian hamsters, and non-human primate (Macaca leonina). In addition, the viral challenge study using the hamster model showed that Nanocovax protected the upper respiratory tract from SARS-CoV-2 infection. No adverse effects were induced by Nanocovax in swiss mice (Musmusculus var. Albino), Rats (Rattus norvegicus), and New Zealand rabbits. These pre-clinical results indicated that Nanocovax is safe and effective.