(FILES) In this file photo taken on November 27, 2021, members of European Border and Coast Guard Agency Frontex stand outside the new closed migrant camp in the Greek island of Kos. - The Swiss vote on May 15, on whether to boost their participation in the European border agency Frontex, amid fears a "no" could ultimately push Switzerland out of the Schengen open-borders area. (Photo by ARIS MESSINIS / AFP)