Nucleocapsid as a next-generation COVID-19 vaccine candidate.

Multiple new variants of the SARS-CoV-2 virus have emerged globally, due to viral mutation. The majority of COVID-19 vaccines contain SARS-CoV-2 spike protein, which is susceptible to mutation. It is known that protection against COVID-19 after two doses of mRNA vaccine continuously wanes over time. If viral variants contain mutated spike protein, current vaccines may not provide robust protection. This perspective suggests the inclusion of SARS-CoV-2 nucleocapsid protein in future COVID-19 vaccines and boosters, as nucleocapsid is much less vulnerable to mutation and may provide stronger immunity to novel viral variants.