NOVAVAX Announces Preclinical Study Results for a Respiratory Syncytial Virus ('RSV') Vaccine Candidate Directed Against the Fusion (...( Preclinical Study Shows the Investiga...)

Preclinical Study Shows the Investigational RSV-F Virus-like Particle Vaccine Induced Neutralizing Antibodies and Protected Mice upon Challenge

ROCKVILLE, Md., Feb. 27 /PRNewswire-FirstCall/ -- Novavax, Inc. (Nasdaq: NVAX) announced results from a preclinical study of a Respiratory Syncytial Virus ("RSV") vaccine candidate directed against the viral fusion (F) protein. The virus utilizes the F protein to fuse with cells in the respiratory tract and cause illness. Novavax's RSV-F VLPs were made using a proprietary matrix (i.e., "core") protein decorated with the human RSV F protein. The VLPs mimic the three-dimensional structure of RSV but cannot replicate and cause disease because they contain no genetic material.

In this study, mice were vaccinated with two injections of RSV-F VLPs (10 microgram dose; no adjuvant), RSV-F VLPs with different adjuvants, inactivated RSV, live RSV, or a placebo. Neutralizing antibody responses against RSV, which are important for preventing infection and lower respiratory illness, were highest in the "VLP plus adjuvant" group; responses with VLPs alone were higher than responses observed with either live or inactivated RSV immunization. The VLPs induced strong cell mediated immune responses with activation of CD8+ cytotoxic T-lymphocytes against the F protein, which are important for protection because they kill cells infected with RSV. The RSV-F VLP vaccine candidate also protected against RSV infection, reducing the quantity of RSV virus found in the lungs of immunized mice after a challenge with live virus.

A monoclonal antibody against F protein with annual sales of $500 million is available that protects against RSV-related hospitalizations in infants and young children at high risk of severe disease. However, several injections are required and the lifespan of th
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