S-567123

S-567123 is an investigational recombinant protein subunit vaccine candidate developed by Shionogi for the prevention of COVID-19. It is designed as a variant-adapted vaccine, specifically targeting the JN.1 lineage of SARS-CoV-2. The vaccine utilizes a recombinant protein technology where the spike protein of the virus is expressed and purified to serve as the antigen. S-567123 is being evaluated in clinical trials as a booster dose in individuals who have previously completed a primary vaccination series, aiming to provide updated protection against circulating variants. It is typically administered via intramuscular injection and is being compared in studies against other variant-adapted vaccines such as Comirnaty and Nuvaxovid.