Does anyone have answer to this question? For example: an US traveler (fully vaccinated and tested negative within 72 hour from departure) fly into Rome and go through custom successfully. He/she then continue the trip to Paris after a few days, and fly to Madrid again later. Does this US traveler needed to take any COVID-19 test again to go from Rome to Paris and Paris to Marid? Or he/she can travel freely without having to do anything?