The French pharma giant, Sanofi, has started a $15.50 per share cash tender offer when it comes to Emeryville, California-based vaccine developer Dynavax, which already goes on to market an adult vaccine that protects against the hepatitis B virus – HBV called Heplisav-B, sales of which came in at almost $95 million in the third quarter.
First approved by the FDA in 2017, Heplisav-B has gone ahead and steadily gained momentum, all thanks to a two-dose regimen that was delivered within a month, which differentiates it from its rival shots such as Engerix-B from GSK and Recombivax HB from MSD, which need three doses over a period of six months.
Dynavax has gone on to say that its shot is leading the market when it comes to adult HBV vaccines, and as it has not been approved for usage in children, it will not get affected due to the recent alterations to pediatric immunization recommendations within the US, which could also suppress the usage of HBV shots and, as per some experts, would result in cases of hepatitis B beginning to grow again after decades of dips.
Notably, the big attraction for Sanofi, however, is Z-1018, which is Dynavax’s experimental shingles vaccine that could be a rival to the blockbuster Shingrix jab from GSK, which went on to dominate the worldwide market and made sales of $4.5 billion in 2024.
It is well to be noted that in a recently announced phase 1/2 trial, Z-1018 demonstrated comparable efficacy when it came to Shingrix but was associated with lesser local as well as systemic post-injection reactions, thereby potentially giving it a tolerability edge. Apparently, Dynavax is now going through the second stage of the trial, looking at two doses that are eight weeks apart in people aged more than 70 years who are at risk of developing shingles, and is going to move ahead with registration trials if those inferences come out positive.
There are almost 1 million cases of shingles per year in the US, as per data coming from the Centres for Disease Control and Prevention – CDC and Shingrix is indeed the dominant vaccine, having a market share of almost 95%.
Interestingly, the pipeline of vaccine developer Dynavax also includes an oral COVID-19 vaccine, which was licensed earlier in 2024 from Vaxart, that is in mid-stage clinical testing, and also candidates for plague, pandemic influenza, and Lyme disease.
According to the French group’s vaccines head, Thomas Triomphe, Dynavax elevated the adult immunization presence of Sanofi by way of adding differentiated vaccines that complement its expertise.
He adds that the marketed adult hepatitis B vaccine, along with the shingles candidate, goes on to bring new alternatives to their portfolio and highlight their commitment to offering vaccine protection throughout the lifespan.
Notably, it is the second acquisition for Sanofi when it comes to the vaccines space in 2025, coming after it bought Vicebio, the UK developer, along with its experimental respiratory syncytial virus – RSV jab VXB-241 for $1.6 billion in July 2025.
As per Sanofi, the Dynavax deal is anticipated to close in Q1 of 2026. Shares in the US company went up over 40% in pre-market trading on December 26, 2025.
