A novel DNA and protein combination COVID-19 vaccine formulation provides full protection against SARS-CoV-2 in rhesus macaques.

The current study aims to develop a safe and highly immunogenic COVID-19 vaccine. The novel combination of a DNA vaccine encoding the full-length Spike (S) protein of SARS-CoV-2 and a recombinant S1 protein vaccine induced high level neutralizing antibody and T cell immune responses in both small and large animal models. More significantly, the co-delivery of DNA and protein components at the same time elicited full protection against intratracheal challenge of SARS-CoV-2 viruses in immunized rhesus macaques.

Evaluate severe acute respiratory syndrome coronavirus 2 infectivity by pseudoviral particles.

Since the outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in humans in late 2019, it has rapidly spread worldwide. To identify the biological characteristics of SARS-CoV-2 in a normal laboratory environment (biosafety level 2 [BSL-2]), a lentiviral-based nucleocapsid was used to carry the spike protein of SARS-CoV-2 onto the surface of pseudoviral particles as a surrogate model to evaluate the infective characterization of SARS-CoV-2. This study indicated that SARS-CoV-2 has extensive tissue tropism for humans and may infect monkeys and tree shrews but not rodents.