Novavax has signed a multi-billion dollar deal with French drugmaker Sanofi to co-commercialize Novavax's protein-based COVID-19 vaccine starting in 2025. Sanofi will pay Novavax an upfront payment of $500 million and up to $700 million in additional payments based on development, regulatory, and launch milestones. Sanofi will also take a less than 5% equity stake in Novavax and provide royalty payments on future vaccine sales. The deal allows Sanofi to develop combination shots using Novavax's COVID vaccine with Sanofi's flu shot or other vaccines in its portfolio.