IVX-421

IVX-421 is a virus-like particle (VLP)-based investigational vaccine candidate against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), developed by Icosavax using its multivalent VLP platform. It incorporates a receptor-binding domain (RBD) protein from the SARS-CoV-2 spike bearing a set of “critical mutations” designed to broaden and strengthen neutralizing antibody responses against the original virus and immune-evasive variants, including beta-lineage strains.[7][9] IVX-421 has been advanced in parallel with the related candidate IVX-411, with Icosavax indicating that clinical development plans may include comparing or combining the two constructs depending on immunogenicity data.[7][9] As of available disclosures, IVX-421 remains in early-stage development as a next-generation COVID-19 vaccine intended to provide more robust and variant-resistant humoral immunity.