I took the Delta flight from Atlanta to JoBerg, which stopped in Dakar for fuel and to let a few passengers off and a few new ones on. We were only on the ground for about an hour, and were not allowed to leave the plane (there was a security check, which was pretty bogus). I found the CDC site less than informative on this specific question when I was asking it a year ago. I was told by Neil Summers at Bowhunting Safari Consultants, our booking agent, and our travel agent at Gracy Travel in TX, which specializes in arranging travel for hunters going to Africa, that we did not require yellow fever vacinations just for this.