The round was led by RA Capital Management and joined by Janus Henderson Investors, Perceptive Advisors, Viking Global Investors, Cormorant Asset Management, Omega Funds, and Surveyor Capital (a Citadel company). Icosavax's existing investors also participated, including Qiming Venture Partners USA, Adams Street Partners, Sanofi Ventures, and ND Capital. A previously announced funding from Open Philanthropy was included in this round. In conjunction with the financing, Peter Kolchinsky, Ph.D., founder and Managing Partner of RA Capital Management, will join the company's Board of Directors.

Icosavax is focused on developing safe and effective vaccines against infectious diseases that cause severe, life-threatening respiratory illnesses. Icosavax is advancing VLP vaccine candidates against respiratory syncytial virus (RSV), human metapneumoviruÂ-Â-s (hMPV), and SARS-CoV-2 (COVID-19). These vaccine candidates have shown induction of high and durable neutralizing antibody titers in preclinical studies and could protect the most vulnerable populations, including older adults. Icosavax was founded on breakthrough computationally designed VLP technology developed at the Institute for Protein Design. Icosavax exclusively licensed the technology for use in several vaccine fields from the University of Washington. For SARS-CoV-2, Icosavax has a worldwide license with an exclusive option for IVX-411 in North America and Europe from the University of Washington.