Sanofi has agreed to acquire Dynavax Technologies for $2.2 billion to strengthen its presence in the adult vaccination market and diversify its vaccine portfolio.

Target Information

Sanofi, a globally recognized pharmaceutical company, has announced its decision to acquire Dynavax Technologies, a specialist in vaccines for infectious diseases, for a total of $2.2 billion. This acquisition is strategically important for Sanofi as it seeks to enhance its presence in the adult vaccination sector and diversify its product offerings beyond its current reliance on flu vaccines. The purchase price represents a 39% premium over Dynavax's closing stock price as of December 23, 2025. This transaction grants Sanofi immediate access to HEPLISAV-B, the only two-dose adult hepatitis B vaccine that has received approval in the United States.

In addition to HEPLISAV-B, the deal positions Sanofi to benefit from Dynavax’s shingles vaccine candidate Z-1018, currently in phase 1/2 trials, allowing Sanofi to compete more effectively against GSK’s Shingrix, a leading vaccine in this segment. The acquisition signifies a focused effort to enhance the product pipeline for adult vaccinations, which are currently viewed as underrepresented in the industry.

Industry Overview

The adult vaccination market has historically lagged behind childhood immunization, creating significant opportunities for growth. In the United States, adult vaccination rates remain low despite the rising prevalen