Article
作者: Palomero, Jesús ; Sánchez-Cordón, Pedro J ; Nogales-Altozano, Pablo ; Rodríguez-Martín, Daniel ; Lozano, Daniel ; Larraga, Vicente ; Carlón, Ana B ; Loayza, Francisco J ; Sevilla, Noemí ; Larraga, Jaime ; Ruiz-García, Silvia ; Vallet-Regí, María ; Alcolea, Pedro J ; Alonso, Ana ; Louloudes-Lázaro, Andrés ; Redondo, Natalia ; Rojas, José M ; Montoya, María ; Manzano, Miguel ; Martín, Verónica
SARS-CoV-2 vaccines currently in use have contributed to controlling the COVID-19 pandemic. Notwithstanding, the high mutation rate, fundamentally in the spike glycoprotein (S), is causing the emergence of new variants. Solely utilizing this antigen is a drawback that may reduce the efficacy of these vaccines. Herein we present a DNA vaccine candidate that contains the genes encoding the S and the nucleocapsid (N) proteins implemented into the non-replicative mammalian expression plasmid vector, pPAL. This plasmid lacks antibiotic resistance genes and contains an alternative selectable marker for production. The S gene sequence was modified to avoid furin cleavage (Sfs). Potent humoral and cellular immune responses were observed in C57BL/6J mice vaccinated with pPAL-Sfs + pPAL-N following a prime/boost regimen by the intramuscular route applying in vivo electroporation. The immunogen fully protected K18-hACE2 mice against a lethal dose (105 PFU) of SARS-CoV-2. Viral replication was completely controlled in the lungs, brain, and heart of vaccinated mice. Therefore, pPAL-Sfs + pPAL-N is a promising DNA vaccine candidate for protection from COVID-19.
