SARS COV 2 virus is a RNA virus then how we are using a DNA zydus vaccine?

SARS COV 2 virus is a RNA virus then how we are using a DNA zydus vaccine ?

It is made via recombinant plasmid DNA containing part of viral genome to confer immunity. So, it isn’t necessary for vaccine to have Exact same genetic composition as virus.

We can use cDNA, incorporate the viral genees for spike proteins and other antigens

thank you sir