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The Evolution of Virus-Like Particle Vaccine Technology

By August 5, 2014Cytomegalovirus ("CMV")

VBI’s eVLP vaccine technology enables the design of enveloped (“e”) Virus-Like Particle (“VLP”) vaccines that closely mimic the structure of enveloped viruses, which VBI believes can be used to elicit potent and long-lasting immunity.

Vaccines work by mimicking pathogens, or invaders of the body, that have the potential to cause disease. By tricking the immune system into believing it is under attack and creating memory cells (immunity), vaccines help the body defend against a particular pathogen without subjecting a person to full-blown infection or illness.

A vaccine typically contains an agent that resembles a disease-causing microorganism and is often made from weakened or killed forms of the virus or its surface proteins. Vaccines are sometimes paired with an adjuvant which stimulates the immune system to respond to the vaccine more vigorously.

Since their introduction, virus-like particles (VLPs) have shown themselves to be a useful tool in the development of vaccines. Unlike weakened or killed forms of viruses, VLPs are engineered and synthesized in the lab. VLPs contain repetitive high density displays of viral surface proteins that mimic the organization found in native viruses. Because VLPs lack genetic material, they may provide a safer alternative to live-attenuated or inactivated vaccines.

First-generation VLP approaches have yielded successful vaccines including Gardasil® (HPV), Cervarix® (HPV), Engerix-B® (Hepatitis B), and Recombivax HB® (Hepatitis B). However, first-generation VLPs offer limited rational design potential and cannot be applied to all enveloped viruses.

VBI’s eVLP Platform

VBI’s eVLP Platform seeks to improve upon prior VLP technologies by providing a stable foundation that mimics enveloped viruses, and VBI believes it is suitable for a wide array of vaccine candidates including CMV, HCV, Dengue, RSV, and West Nile. VBI’s eVLPs are highly immunogenic and are capable of generating immunity comparable to or better than that associated with natural infection. They do this by closely mimicking the structure of the target virus.

eVLPs are also customizable, which VBI expects will allow it to rationally design a vaccine by including different portions (antigens) of a vaccine target of interest and controlling their relative expression. Initial results from pilot scale production at a third-party manufacturer have demonstrated commercially-suitable yields.

VBI is focused first on developing a prophylactic eVLP vaccine to prevent Cytomegalovirus (CMV) infection. CMV is a leading cause of prenatal developmental delays. Based on positive preclinical data, VBI has initiated work for GMP manufacturing of its lead candidate for use in formal preclinical and Phase I trials.