Novavax Says Vaccine Protects Against Deadly Bird Flu [Update: and Swine Flu]

Novavax and the NIH Agree to Evaluate a Virus-like Particle (VLP)
Vaccine Candidate against the Novel Influenza A (H1N1) Virus

Company completes initial steps towards producing Influenza A (H1N1) VLP vaccine
for animal and human testing

ROCKVILLE, MD (June 4, 2009) – Novavax, Inc. (NASDAQ: NVAX) and the Division
of Microbiology and Infectious Diseases (DMID) of the National Institute of Allergy and
Infectious Diseases (NIAID), National Institutes of Health (NIH) have signed an
agreement to cooperate in the evaluation of a virus-like particle (VLP) vaccine candidate against the novel influenza A (H1N1) virus. Novavax has produced influenza A (H1N1) VLP vaccine against the strain recommended by the Centers for Disease Control and Prevention (CDC).

Novavax scientists produced the first batch of H1N1 VLPs within the company’s
laboratories in May, just three weeks after the CDC announced the genetic sequence of a novel influenza A (H1N1) virus. This strain of influenza was isolated from an infected
person located in California. These VLPs contain the hemagglutinin (HA),
neuraminidase (NA) and matrix 1 (M1) proteins found in the newly emerged H1N1
influenza strain. The size and structure of the VLPs are nearly identical to those of the
novel H1N1 virus but the VLPs are not infectious as they lack the genes necessary for
replication. Novavax has made purified influenza A (H1N1) VLPs, which are being sent
to scientists at the CDC and DMID for studies in animal models.

“The Company has committed necessary resources to respond as rapidly as possible to
construct and manufacture VLP vaccine against this new H1N1 influenza virus”, said
Rahul Singhvi, President and CEO of Novavax. “Our proprietary recombinant cell
culture technology has enabled production of custom VLPs against this strain of
influenza within weeks. This ability to respond rapidly is an important factor in the
evaluation of alternative investigational vaccines against this emerging threat to public
health.”

The influenza A (H1N1) virus was first detected in April 2009, in Mexico, the United
States and Canada and has subsequently spread rapidly to over sixty countries worldwide. Although illnesses to date have been of a similar severity as that of typical seasonal influenza, it is unclear if the strain will evolve to become more deadly over the course of the next several months. Therefore, technology that can lead to rapid production of vaccines is important to reduce the spread of the virus and to potentially prevent a pandemic from occurring. Novavax believes that its influenza VLP vaccine technology could be part of the solution for influenza pandemics as will be demonstrated in this instance by release of a vaccine lot produced under cGMP against the novel influenza A H1N1 strain within approximately 12 weeks or less of the CDC announcement of the new strain.

Novavax has completed genetic engineering and manufacture of the master seed stock
necessary to produce larger quantities of the investigational influenza A (H1N1) VLP
vaccine under cGMP conditions in its manufacturing facility in Rockville, MD. More
details on the progress in making influenza A (H1N1) VLP vaccine may be found at the
Novavax web site: www.novavax.com.