The exact source of the footage shown between the 0:29 mark and the end of that YouTube video is a video pool package filmed by the German Press Agency (Deutsche Presse-Agentur / dpa). [1]

The footage features photojournalist Tim Brakemeier's coverage for the dpa pool, capturing Tropenmediziner Florian Steiner and Stationsleiter Thomas Klotzkowski conducting a simulated bio-emergency exercise at the Sonderisolierstation 59 (Special Isolation Ward) at Charité Berlin on August 11, 2014. [1, 2, 3]

The specific visual sequence in your video—including the side-angle perspective of the medical specialists being sprayed down during the chemical shower decontamination process—belongs to this specific dpa video package distributed across German broadcasters. You can find matching production metadata, stills, and tracking details through the historical Tagesspiegel Archive Report and licensing agencies that host dpa's 2014 video pool files. [1]