Sanofi acquired Dynavax Technologies in an all-cash tender offer of $15.50 per share (~$2.2B equity value; a 39% premium to the Dec 23, 2025 close), announced Dec 24, 2025 and completed Feb 10, 2026. The deal adds Dynavax’s marketed adult hepatitis B vaccine HEPLISAV-B — differentiated by a 2-dose, 1-month regimen — plus a Phase 1/2 shingles candidate (Z-1018) to Sanofi’s adult-immunization portfolio. Funded with available cash.