Pfizer and BioNTech entered a collaboration to develop mRNA-based influenza vaccines using BioNTech's proprietary mRNA platform technology. Pfizer paid $120M upfront and BioNTech is eligible for up to $305M in development and commercial milestones. This deal established the Pfizer-BioNTech partnership that later became the foundation for the COVID-19 vaccine collaboration (BNT162b2/Comirnaty).