A self-amplifying RNA encoding a spike protein of SARS-CoV-2 encapsulated in a lipid nanoparticle vaccine was studied in mice as a potential vaccine candidate to combat COVID-19. The study looked at both the humoral and cellular response of the vaccine compared to the natural infection in COVID-19 patients. Additionally, neutralization capacity of a pseudotyped and wild-type SARS-CoV-2 virus was assessed.