Sanofi Dengue Bid Seen as $2.6 Billion Hit or Major Flop

Sanofi, whose vaccines have all but eradicated polio, recently flew journalists from around the globe to a sparkling new factory in France to tout its next big project -- the world’s first vaccine for dengue.

That takes confidence, considering mid-stage studies for the shot last year yielded results that ranged from perplexing to disappointing. Sanofi is forging ahead. It’s readying commercial production of a vaccine to prevent the debilitating and sometimes fatal mosquito-borne malady that’s had outbreaks in the U.S. and Europe and threatens half the global population.