• Vaccine was well-tolerated with no evident dose-related toxicity or attributable SAEs
• Immunization induced significant increases in neutralizing antibody responses

ROCKVILLE, Md., Dec. 6, 2012 (GLOBE NEWSWIRE) -- Novavax, Inc. (Nasdaq:NVAX) today announced that the journal Vaccine has published the company's data from its 2011 Phase I clinical trial of its respiratory syncytial virus (RSV) fusion (F) recombinant nanoparticle vaccine candidate. The paper was authored by a team of researchers and clinicians at Novavax and Dr. Pedro Piedra of Baylor College of Medicine. Findings from the trial were announced in October 2011 and presented in September 2012 by Novavax at the Respiratory Virus Symposium (RSV 2012) meeting in Santa Fe, New Mexico. The paper is currently available at www.novavax.com under Publications & Presentations/Publications and is expected to be published in the print edition shortly.

Novavax had conducted the blinded, placebo-controlled, dose-escalating Phase I trial to assess the safety and tolerability of aluminum phosphate-adjuvanted and unadjuvanted formulations of its RSV vaccine candidate. A secondary objective of the study was to evaluate total and neutralizing anti-RSV antibody responses and assess the impact of the adjuvant. The authors reported that Novavax' vaccine was well-tolerated, with no evident dose-related toxicity or attributable severe adverse events. At day 60, both RSV A and B microneutralization titers were significantly increased in subjects treated with the Novavax vaccine versus placebo. The authors also reported a 7- to 19-fold increase in the anti-F IgG and a 7- to 24-fold increase in the levels of antigenic site II binding antibodies in vaccine recipients, as well as the induction of serum antibodies capable of competing with palivizumab, a humanized monoclonal antibody (mAb) with known protective efficacy against RSV disease in animals and humans.

"We are encouraged with the tolerability profile demonstrated in this trial as no attributable SAEs or significant dose-related toxicities were observed," said Dr. Gregory Glenn, Novavax' Chief Medical Officer. "In addition, the data suggest that neutralizing responses induced by our RSV F nanoparticle vaccine attain levels previously reported to be associated with a decrease in the risk of RSV hospitalization in selected populations. The presence of high-titered antibodies capable of competitively inhibiting palivizumab binding to the RSV F protein in sera of vaccine recipients but not the majority of sera of unimmunized adults or placebo recipients is novel and should be studied further. This observation suggests that the vaccine induces antibodies with specificities closely similar to palivizumab (Synagis®) that has been shown to have prophylactic efficacy in large clinical trials. Such an observation supports the likely clinical impact of the vaccine-induced antibodies and will assist the planning of future clinical efficacy evaluation of the vaccine."

Novavax is currently conducting a Phase II clinical trial in women of childbearing age to further evaluate the immunogenicity and safety of the RSV F vaccine candidate. This data will inform the future development of the RSV F vaccine to address infant RSV-related lower respiratory tract disease via maternal immunization. The company is also carrying out a Phase I clinical trial in elderly adults to evaluate the immunogenicity and safety of the vaccine candidate in this important population.

About RSV

RSV is a major respiratory pathogen in infants, children, and adults. Childhood RSV disease is found primarily in full-term infants and children with no underlying medical condition and is the leading cause of infant hospitalization in the US, with approximately 90,000-147,000 attributable hospitalizations annually, with 75% of these inpatient stays in infants under 6 months of age. Maternal immunization for RSV may address this major unmet need and would be aligned with evolving medical practices for influenza and whooping cough (pertussis) vaccines, that are given to the mother and benefit the newborn via trans placental transfer of maternal antibodies to the fetus in-utero. Globally, maternal immunization for neonatal tetanus has reduced the disease burden in infants by more than 90%. RSV infections in adults represent re-infections and are generally mild to moderate in severity, except in persons with high-risk conditions including the elderly and adults with underlying chronic cardiac or pulmonary disease. It is estimated that between 11,000-17,000 adults die of RSV infection annually in the U.S., with up to 180,000 admitted to the hospital with respiratory symptoms. Currently, there is no approved RSV vaccine available.

About Novavax

Novavax, Inc. (Nasdaq:NVAX) is a clinical-stage biopharmaceutical company creating vaccines to address a broad range of infectious diseases worldwide. Using innovative recombinant nanoparticle technology, as well as new and efficient manufacturing approaches, the company produces vaccine candidates to combat diseases, with the goal of allowing countries to better prepare for and more effectively respond to rapidly spreading infections. Novavax is committed to using its technology platforms to create geographic-specific vaccine solutions and is therefore involved in several international partnerships, including collaborations with Cadila Pharmaceuticals of India, LG Life Sciences of Korea and PATH. Together, these organizations support Novavax' worldwide commercialization strategy and have the global reach to create real and lasting change in the biopharmaceutical field. Additional information about Novavax is available on the company's website, www.novavax.com.

Forward-Looking Statements

Statements herein relating to the future of Novavax and its ongoing development of its RSV F vaccine candidate are forward-looking statements. Novavax cautions that these forward-looking statements are subject to numerous risks and uncertainties, which could cause actual results to differ materially from those expressed or implied by such statements. These risks and uncertainties include those identified under the heading "Risk Factors" in the Novavax Annual Report on Form 10-K for the year ended December 31, 2011, and filed with the Securities and Exchange Commission. We caution investors not to place considerable reliance on the forward-looking statements contained in this press release. You are encouraged to read our filings with the SEC, available at www.sec.gov, for a discussion of these and other risks and uncertainties. The forward-looking statements in this press release speak only as of the date of this document, and we undertake no obligation to update or revise any of the statements. Our business is subject to substantial risks and uncertainties, including those referenced above. Investors, potential investors, and others should give careful consideration to these risks and uncertainties.