Key Summary
- The acquisition will help Sanofi diversify its vaccine business, which has been hit by the US overhauling of its childhood immunisation policy
- Hepatitis B and shingles offer a significant opportunity for adult vaccination
- Sanofi plans to fund the acquisition with available cash resources
Sanofi has agreed to acquire US-based vaccine maker Dynavax Technologies for £1.63 billion, as the French pharma giant looks to boost its presence in the adult immunisation segment.
Dynavax's Heplisav‑B vaccine is given to those aged 18 years and older to help prevent infection from the hepatitis B virus, and its shingles vaccine is currently undergoing trials.
Heplisav‑B injection is administered in two doses, one month apart, compared with other vaccines that are given in three doses over six months.
“Dynavax enhances Sanofi’s adult immunisation presence by adding differentiated vaccines that complement Sanofi’s expertise,” said Thomas Triomphe, executive vice president, Vaccines, Sanofi.
“Its marketed adult hepatitis B vaccine and shingles candidate brings new options to our portfolio and underscores our commitment to providing vaccine protection across the lifespan.”
Dynavax chief executive officer Ryan Spencer said, “Joining Sanofi will provide the global scale and expertise needed to maximize the impact of our vaccine portfolio.”
Industry analysts say the acquisition will help the French drugmaker diversify its vaccine business at a time when the US is remaking policy for childhood immunisation, where Sanofi has a good presence.
The Trump administration has dropped a long-standing universal recommendation for hepatitis B vaccination in infants, and is considering other changes for 2026.
Earlier this year, Sanofi and British rival GSK noted pressure in the US flu vaccine market.
Hepatitis B and shingles represent significant adult vaccination opportunities, and in the US alone, nearly 100 million adults born before 1991 remain unvaccinated.
Chronic infection with the hepatitis B virus can cause liver damage and lead to cirrhosis and liver cancer.
Shingles, which is caused by the varicella zoster virus, affects one in three adults over their lifetime, according to the World Health Organization.
In most people, shingles causes a painful, itchy rash; however, in some cases it can lead to long-term nerve pain, serious eye infections that can damage the vision, and, rarely, to dangerous inflammation of the brain.
The transaction has been unanimously approved by the Dynavax board of directors, and the tender offer is subject to customary closing conditions.
Sanofi plans to fund the acquisition with available cash resources, and this is not expected to have any impact on its financial guidance for 2025.
Once the tender offer is completed, a wholly owned subsidiary of Sanofi will merge with and into Dynavax.
