Sanofi has agreed to acquire hepatitis B vaccine manufacturer Dynavax for an equity value of around $2.2bn, bolstering the former’s pipeline amid significant vaccine policy changes in the US.
The transaction, for a price of $15.50 per share in cash, is expected to close in the first quarter of 2026.
Through the deal, Sanofi will acquire Dynavax’s hepatitis B vaccine HEPLISAV-B. The product won approval in the US and Europe in 2017 and 2021, respectively. Sanofi does not currently have a hepatitis B vaccine in its portfolio. The French drugmaker previously won approval for a hepatitis B vaccine in a joint venture with MSD, though the latter company now commercialises the jab, which is known under the HBVaxPro and Recombivax HB brand names in Europe and the US, respectively.
Heplisav-B is administered via a two-dose regimen delivered within one month, unlike GSK’s Engerix-B and MSD’s Recombivax HB. These rival products are given in three doses over six months.
With the Dynavax acquisition, Sanofi is adding a strong revenue avenue for the virus that causes serious liver infection. HEPLISAV-B generated sales of $268.4m in 2024, with Dynavax forecasting net product revenue of between $305m and $325m for 2025. GlobalData forecasts HEPLISAV-B will reach $677m in annual sales in 2031.
GlobalData is the parent company of Pharmaceutical Technology.
William Blair analyst Matt Phipps said: “While the deal value does come slightly below our net present value for Heplisav of $2.6bn, we believe the acquisition makes sense given growing regulatory concerns around vaccines and investor questions on management’s strategy for value creation.”
Earlier in December, the US Centers for Disease and Prevention (CDC) changed its guidance to no longer recommend that all US newborns receive the hepatitis B vaccine. The significant policy changes have created volatility in the infectious disease vaccine sector, along with catalysing backlash from several medical bodies.
The jewel in Dynavax’s pipeline is its shingles vaccine candidate, currently in a Phase I/II trial. In results announced in August 2025, the jab, dubbed Z-1018, demonstrated comparable efficacy to GSK’s blockbuster Shingrix – a product that dominates the shingles market. However, Z-1018 had fewer local and systemic post-injection reactions, which might give it a market advantage on tolerability.
About one in three people in the US develop shingles at least once in their lives, according to the CDC. Shingrix generated £3.4bn globally for GSK in 2024, representing the size of the shingles market.



