Sanofi agreed to acquire Dynavax Technologies for $2.2 billion in cash to bolster its vaccine portfolio, the companies said Wednesday. The deal adds Dynavax’s hepatitis B vaccine assets and manufacturing capabilities to Sanofi’s global vaccine business. The announcement also flagged a regulatory setback: Dynavax recently received a complete response letter for an MS drug, a note the companies addressed alongside the acquisition. Sanofi framed the purchase as a strategic fit to expand immunization offerings and manufacturing scale. Investors and industry managers will evaluate how the acquisition integrates Dynavax’s vaccine pipeline and whether Sanofi will repurpose Dynavax manufacturing to support broader vaccine supply or new platform work.