Moderna announced it has submitted a regulatory application to the FDA seeking authorization for mRNA-1273.815, its updated COVID-19 vaccine designed to target XBB descendant lineage viruses. The monovalent vaccine represents a strategic shift from currently authorized bivalent COVID-19 vaccines, focusing specifically on spike proteins for the XBB.1.5 sublineage of coronavirus.
Regulatory Pathway and Advisory Committee Guidance
The submission aligns with guidance from an FDA advisory committee issued last week, which unanimously recommended updating COVID vaccines to target the Omicron XBB lineage. This lineage currently accounts for the majority of COVID infections across the United States, prompting regulatory authorities to prioritize vaccine updates targeting these dominant variants.
The regulatory filing is supported by preliminary data from preclinical studies demonstrating mRNA-1273.815's effectiveness in generating immune responses against current XBB variants of concern. According to Moderna, the preliminary clinical data showed a robust immune response by the company's XBB.1.5 monovalent vaccine against XBB descendant lineage viruses.
Manufacturing and Supply Readiness
Moderna management has indicated the company has built ample supply for mRNA-1273.815 and stands ready to ship doses for the fall vaccination season, contingent upon FDA authorization. This preparation reflects the company's anticipation of regulatory approval and commitment to meeting seasonal vaccination demands.
Competitive Landscape
The vaccine update initiative extends beyond Moderna, with major competitors Pfizer/BioNTech and Novavax also developing XBB-targeting vaccines. During the FDA committee meeting, all three manufacturers presented preclinical findings supporting their respective XBB.1.5 variant-targeting vaccines. The preclinical data from these manufacturers indicates that monovalent vaccines demonstrate superior effectiveness compared to bivalent formulations.
Pfizer/BioNTech expects to have their updated vaccine ready for supply by the end of next month, while Novavax is currently manufacturing its protein-based monovalent XBB.1.5 COVID vaccine candidate at commercial scale for the 2023 fall vaccination campaign. However, the FDA has not yet approved or authorized vaccines from either Novavax or Pfizer/BioNTech.
Market Performance and Industry Context
Moderna shares have declined 32.9% year-to-date, significantly underperforming the broader industry's 7.6% decline. This performance reflects ongoing market challenges facing COVID vaccine manufacturers as the pandemic transitions to endemic status and vaccination demand patterns evolve.
The shift toward XBB-targeting vaccines represents a critical adaptation to the evolving SARS-CoV-2 landscape, where new variants continue to emerge and dominate transmission patterns. The unanimous advisory committee recommendation underscores the scientific consensus that vaccine updates are necessary to maintain effectiveness against circulating strains.
