Dengue is spreading and Sanofi is pulling the market’s only vaccine. What’s next?

The mosquito-transmitted virus is among the top 10 global health threats designated by the World Health Organization. There were a record 6.43 million cases of dengue and nearly 7,000 deaths worldwide in 2023 — the largest outbreak ever recorded. Dengue is also spreading faster in places where it hasn’t before thanks to factors like climate change, urbanization and increased global travel, according to the WHO.