Virus-like Particles (VLPs)
VLPs enable high-density, multivalent display of antigens in a manner that closely resembles viruses. This induces stronger and more durable immunological responses compared to traditional soluble antigens. In addition, VLPs contain no genetic material, so they are non-infectious and can provide a safer alternative to live-attenuated or inactivated vaccines.
Icosavax was founded on breakthrough technology, developed at the Institute for Protein Design (IPD) at the University of Washington, that solves the problem of constructing and manufacturing VLPs displaying complex antigens. The technology generates computationally designed proteins that separate the folding of individual protein subunits from the assembly of the final macromolecular structure. The individual proteins are expressed and purified using traditional recombinant technologies and then self-assemble into VLPs when mixed together.
Naturally occurring VLPs have delivered effective licensed vaccines, including against human papillomavirus (HPV) and Hepatitis B. However, VLPs have been difficult to use for the display of complex heterologous antigens, like in the case of RSV.
Crank MC, et al. A proof of concept for structure-based vaccine design targeting RSV in humans. Science (2019), 505-509.
Rappuoli R. and D. Serruto. Preview: Self-Assembling Nanoparticles Usher in a New Era of Vaccine Design. Cell (2019), 1245-1247.
Our technology allows us to readily manufacture VLPs displaying complex antigens to target a whole class of vaccine targets, such as RSV and SARS-CoV-2, with significant unmet medical needs.