Sanofi Pasteur: The Dengue Vaccine Dilemma

In 2012, Sanofi Pasteur was racing to develop a vaccine against dengue, a mosquito-borne disease, and was evaluating this product in a Phase IIb trial conducted with school children in Thailand. But while the candidate vaccine met the high safety expectations and a good balanced immune answer, it had a proof of efficacy of only 30%, far below the 70% mark the company had targeted. Guillaume Leroy, vice president of the Dengue Company at Sanofi Pasteur, reflected on the Phase IIb trial's surprising outcome and the way forward. He had to decide whether to go ahead with the vaccine trials and production, and if so, needed to develop a strategic plan on how to price and deliver the vaccine for a rapid roll-out.