I traveled from Colombia to Costa Rica yesterday on Copa. Upon my arrival at BOG, I was asked for my Yellow Fever Immunization Card. "Huh?" Turns out that Costa Rica now requires a Yellow Fever immunization for travelers coming from Colombia. They are in the midst of a political rift, and that is clearly the reason for the new travel requirement. It takes TEN DAYS for a Yellow Fever immunization to work. I had two hours. Latin America it is, however, so $120, a baggage handler and no needle got me immunized in ten minutes. I would have preferred the real immunization, but Copa failed to advise me prior to my departure 3 days prior. I love Copa Airlines, but come.... on.... At any rate, I hope this saves someone some unnecessary grief. Keep checking everywhere you can prior to making this trip, as the family feud can mean new regulations with very little warning. I made the same trip 5 weeks ago with no such requirement.