Former FDA chief Scott Gottlieb on why J&J's next Covid-19 clinical trial is twice as large as others

Johnson & Johnson is planning to launch the largest coronavirus vaccine clinical trial to date. The company is planning to enroll up to 60,000 people in the trial by late September, which is twice as large as most other late-stage studies. Dr. Scott Gottlieb, member of the boards of Pfizer and biotech company Illumina and former FDA commissioner, joins "Squawk Box" to discuss.