Nuvaxovid™ COVID-19 Vaccine Showed Better Tolerability than mNEXSPIKE in Head-to-head Sanofi-led Phase 4 Study

Today, Sanofi presented positive results from COMPARE, the first head-to-head, double-blind, randomized Phase 4 study powered to directly compare the tolerability profiles of Novavax's protein-based non-mRNA COVID-19 vaccine Nuvaxovid™ (NVX-CoV2705) and mNEXSPIKE (mRNA-1283), Moderna's latest mRNA COVID-19 vaccine. The study showed that Nuvaxovid demonstrated statistically significant lower systemic reactogenicity (the expected side effects that might occur following vaccination) compared to mNEXSPIKE across all pre-specified endpoints. The results were presented by Sanofi at the European Society of Clinical Microbiology and Infectious Diseases Global Congress in Munich, Germany.

These data support the well-established reactogenicity profile of our vaccine and could have a positive impact on improving vaccination uptake as Sanofi continues to lead commercialization of Nuvaxovid this upcoming vaccination season.

Forward-Looking Statements

Statements herein relating to the future of Novavax, its operating plans and prospects, the reactogenic response of its vaccine technology as compared to mNEXSPIKE enhancing vaccine preference by healthcare providers and individuals are forward-looking statements. Novavax cautions that these forward-looking statements are subject to numerous risks and uncertainties that could cause actual results to differ materially from those expressed or implied by such statements. These risks and uncertainties include, without limitation, challenges satisfying various safety, efficacy, and product characterization requirements, including those related to process qualification and assay validation, necessary to satisfy applicable regulatory authorities; difficulty obtaining scarce raw materials and supplies; resource constraints, including human capital and manufacturing capacity, on the ability of Novavax to pursue planned regulatory pathways; challenges or delays in obtaining regulatory authorization for its product candidates for future COVID-19 variant strain changes; challenges or delays in clinical trials; manufacturing, distribution or export delays or challenges; Novavax's exclusive dependence on Serum Institute of India Pvt. Ltd. for co-formulation and filling and the impact of any delays or disruptions in their operations on the delivery of customer orders; challenges meeting contractual requirements under agreements with multiple commercial, governmental, and other entities and those other risk factors identified in the "Risk Factors" and "Management's Discussion and Analysis of Financial Condition and Results of Operations" sections of Novavax's Annual Report on Form 10-K for the year ended December 31, 2025, and subsequent Quarterly Reports on Form 10-Q, as filed with the Securities and Exchange Commission (SEC). We caution investors not to place considerable reliance on forward-looking statements contained in this statement. You are encouraged to read our filings with the SEC, available at www.sec.gov and www.novavax.com, 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.