France's Sanofi hopes to launch the first vaccine against dengue fever, the world's fastest-growing tropical disease, in 2015. A large clinical study showed it provided moderate protection, but as Joanna Partridge questions remain over how well it can help fight dengue and whether the drug will be a blockbuster for Sanofi.
It's the fastest-growing tropical disease, killing an estimated 20,000 people a year. Nearly half the world's population is at risk of contracting dengue fever. 100 million people each year are infected according to the World Health Organisation. France's Sanofi has been developing a dengue vaccine for the past 20 years. Now a large clinical study in five Asian countries showed the three-dose vaccine provides moderate protection against the disease. Nicholas Jackson is head of dengue research and development at Sanofi's vaccines unit, Sanofi Pasteur. SOUNDBITE: Dr. Nicholas Jackson, Head of Dengue Research and Development, Sanofi Pasteur, saying (English): "In addition to reducing just over half of all disease, we've also shown that we can reduce disease by 88 percent in the severe form, and this is critically important when you think about the gravity of a severe infection." The trial showed the vaccine offered poor protection to young children - who are most at risk. And it wasn't efficient in tackling one of the four strains of the disease. The results suggest it works best on patients with previous exposure, perhaps limiting its use as a travellers' vaccination. The vaccine's efficacy isn't just key for patients. Its development has been a gamble for Sanofi. It's invested 1.3 billion euros in the project and even built a dedicated site in southern France where it has already started producing it. That's even though the vaccine's commercial prospects aren't certain. But it's several years ahead of the competition and some analysts believe it could sell one billion euros' worth a year. That would significantly boost Sanofi's vaccines business, which had sales of 3.7 billion euros in 2013. Federica Benassi is a Life Sciences Analyst at IHS. SOUNDBITE: Federica Benassi, Life Sciences Analyst, IHS, saying (English): "Sanofi's very likely to the first one that will be marketing a vaccine which targets this disease dengue fever. So is very important because this may pave the way for Sanofi to become a leader in this segment of the market and for this vaccine to become a blockbuster." Sanofi is now waiting for the results of a final study in Latin America, due before the end of the year. It says it will wait until then before seeking approval from regulators in countries where the disease is endemic. Investors will also be hoping 20 years on, the vaccine will soon be able to help patients and Sanofi.