Abstract: Compositions and methods for inducing a protective mucosal immunity against an antigen in a subject include the step of administering to a mucosal tissue an effective amount of a vaccine composition including the antigen or polynucleotide encoding an antigen associated or encapsulated within carriers such as poly(amine-co-ester) polymers in the form of particles (e.g., solid nanoparticles formed of PACE) or PACE copolymers and/or blends. Typically, the subject has previously been exposed to the antigen, for example, by administering to the same subject via a systemic or mucosal route of administration a priming antigen. In some embodiments, the polynucleotides-based vaccines are messenger RNAs encoding a viral antigen such as a coronavirus spike protein sequence, or a portion thereof. In preferred embodiments, the vaccine composition is administered intranasally.