Sanofi CEO Paul Hudson on two-pronged approach to developing Covid-19 vaccine

Investors are watching the race to develop a coronavirus vaccine closely for signs of when the U.S. economy can begin to get back on track. Sanofi is one of the drugmakers leading the charge with clinical trials, which are expected to start later this year. Sanofi CEO Paul Hudson joins "Squawk Box" to discuss the latest regarding vaccine developments.