Abstract Background Additional SARS-CoV-2 vaccines that are safe and effective as both primary series and booster remain urgently needed to combat the COVID-19 pandemic. Here we describe the safety and durability of the immune response from two doses of a DNA vaccine (INO-4800) targeting the full-length Spike antigen and a subsequent homologous booster dose. Methods INO-4800 was evaluated in 120 healthy participants across three dose groups (0.5 mg, 1.0 mg and 2.0 mg), each stratified by age.
