The purpose of this Phase 2 study is to assess the safety and immunogenicity of MVC-COV1901 vaccine in two different dose forms in participants who are generally healthy or with stable pre-existing health conditions.

Participants who are generally healthy or with stable pre-existing health conditions will be randomized, stratified by comorbidity. All eligible participants will be randomized to receive 2 doses of either High-dose or Mid-dose of MVC-COV190 in a predefined ratio.