Sanofi to acquire Dynavax in USD2.2B deal to strengthen vaccine portfolio

USA—French pharmaceutical giant Sanofi has agreed to acquire Dynavax Technologies, a US-based manufacturer of the hepatitis B vaccine Heplisav-B, for an equity value of approximately USD2.2 billion.

The deal, valued at USD15.50 per share in cash, is expected to close in the first quarter of 2026, pending regulatory approval.

This acquisition underscores Sanofi’s efforts to expand its vaccine offerings at a time when the US is undergoing significant policy shifts around immunization.

Through this agreement, Sanofi will gain full ownership of Heplisav-B, a two-dose hepatitis B vaccine that received US approval in 2017 and European authorization in 2021.

The company currently lacks a hepatitis B vaccine in its portfolio, though it previously co-developed one with MSD through a joint venture.

MSD now markets that vaccine independently under the brand names HBVaxPro in Europe and Recombivax HB in the United States.

Unlike GlaxoSmithKline’s Engerix-B and MSD’s Recombivax HB, which require three doses administered over six months, Heplisav-B is delivered in two doses within one month.

This shorter dosing schedule has made it an attractive alternative for adult immunization programs, particularly among patients seeking faster protection.

The addition of Dynavax will provide Sanofi with a strong revenue stream in the infectious disease vaccine category.

Heplisav-B generated sales of USD268.4 million in 2024, with Dynavax estimating product revenues to reach between USD305 million and USD325 million in 2025.

Market analysts at GlobalData project the vaccine will attain annual sales of USD 677 million by 2031.

Commenting on the acquisition, William Blair analyst Matt Phipps noted that while the USD 2.2 billion price tag is slightly below the firm’s estimated net present value of USD 2.6 billion for Heplisav-B, the strategic move aligns with Sanofi’s goals, given increasing scrutiny of vaccine policies and investor questions about long-term growth prospects.

In December 2025, the US Centers for Disease Control and Prevention (CDC) revised its vaccination guidelines, removing the recommendation that all newborns receive the hepatitis B vaccine.

This decision has triggered debate within the medical community and added uncertainty to the broader vaccine market.

Beyond Heplisav-B, Dynavax is advancing an experimental shingles vaccine known as Z-1018.

In early-stage trials reported in August 2025, Z-1018 showed comparable efficacy to GSK’s leading shingles vaccine, Shingrix, while causing fewer local and systemic side effects.

The shingles market remains substantial, with Shingrix generating approximately £3.4 billion (USD4.3 billion) globally in 2024.

Thomas Triomphe, Sanofi’s executive vice president of vaccines, said the acquisition brings valuable assets to Sanofi’s portfolio, including both a marketed adult hepatitis B vaccine and a promising shingles candidate.

Phipps added that Sanofi’s established vaccine capabilities make it a natural partner to advance these programs globally.