Working to empower a better immune response

Icosavax was founded in 2017 with a mission to protect at-risk populations through the discovery, development, and commercialization of vaccines for severe, life-threatening infectious diseases. We are advancing breakthrough virus-like particle (VLP) technology that enables multivalent, particle-based display of complex viral antigens, which we believe can induce broad, robust, and durable protection against the targeted viruses. Icosavax’s lead program is a combination vaccine candidate targeting respiratory syncytial virus (RSV) and human metapneumovirus (hMPV), and its pipeline includes additional programs in influenza and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

Our ultimate vision is to utilize our VLP technology to produce combination vaccines that may offer one or more of these potential benefits: protect against multiple viral infections, last beyond a single season, cover emerging variants, limit unwanted side effects, and significantly reduce hospitalization and death—especially in the more vulnerable elderly.

Icosavax at-a-glance
  • Developing VLP-based vaccines and combinations with the ultimate vision of creating pan-respiratory vaccines for older adults
  • Unique VLP platform may offer one or more potential benefits. VLPs are intentionally designed to mimic the structure of viruses to enhance the immune response
  • IVX-A12—the only RSV/hMPV combination candidate in the clinic for older adults—is currently in Phase 2
  • Flu and COVID-19 programs in preclinical development
  • Continuing to expand capabilities, including a research team focused on state-of-the-art antigen design and a team optimizing our speed in manufacturing
  • Experienced team with extensive expertise in protein design and vaccine development supported by leading healthcare investors and a distinguished scientific advisory board


Icosavax, Inc.
1930 Boren Ave, Suite 1000
Seattle, WA 98101