Sanofi-Aventis / Acambis plc

Smallpox (Biodefense Vaccines)

$425M $425M 10-year US strategic national stockpile contract for ACAM2000 (April 2008)

Disease Overview

Smallpox is a viral disease eradicated globally in 1980 but maintained in select labs and considered a Category A bioterrorism threat by the CDC. The US government maintains a strategic national stockpile of smallpox vaccine to protect the population in the event of an attack. Acambis's ACAM2000 was the principal supplier to that stockpile.

Competitive Landscape

ACAM2000 was the only FDA-licensed smallpox vaccine in the US at the time of the Sanofi-Acambis deal (FDA approval August 2007), having displaced the older Dryvax product as the primary supplier to the US strategic national stockpile. Bavarian Nordic was the principal competitor with IMVAMUNE (later JYNNEOS, FDA-approved 2019), a non-replicating MVA-based vaccine targeted at immunocompromised populations who could not safely receive the live-virus ACAM2000. Beyond smallpox, the deal gave Sanofi Pasteur a stake in three jointly-developed mid- to late-stage flavivirus vaccines (Japanese encephalitis, West Nile virus, dengue) where Sanofi was already partnered with Acambis, plus early-stage assets in C. difficile, influenza, and genital herpes. Strategically, the deal eliminated partner-overhang on those flavivirus programs, secured a 10-year £212M / $425M CDC stockpile annuity, and supported Sanofi's stated goal of growing biotech/vaccines to 30% of revenue by 2012. Acambis was selected over Oxford BioMedica (whose TroVax cancer vaccine had recently failed renal cancer trials), signaling Sanofi's preference for revenue-generating biodefense assets over speculative oncology vaccines. The acquisition consolidated Sanofi Pasteur's leadership in vaccines and reinforced its travel/biodefense franchise alongside its core pediatric and influenza portfolios.