Novavax reports positive preclinical results from RSV vaccine study

Novavax, a biopharmaceutical company, has announced encouraging results from a preclinical study of a respiratory syncytial virus vaccine candidate directed against the viral fusion protein.

The virus utilizes the fusion (F) protein to fuse with cells in the respiratory tract and cause illness. Novavax’s respiratory syncytial virus (RSV)-F virus like particles (VLPs) were made using a matrix 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, the company said.

In this study, mice were vaccinated with two injections of RSV-F VLPs (10mcg 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.

According to the company, 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.

Rahul Singhvi, president and CEO of Novavax, said: We are very excited about these results, which open up a new avenue of clinical research using our VLP technology and further demonstrate the versatility of our VLP vaccine platform. We believe our approach holds great promise for preventing RSV disease and we look forward to advancing an RSV vaccine candidate into human clinical studies as soon as possible.