A colleague who was travelling for a business meeting from PDX to MUC via AMS on Delta was refused boarding in PDX on Saturday. The agent at check in said he needed to be vaccinated. He had a negative test <24 hours before the flight and that was not the issue. He argued but the agent was adamant. Another colleague flying from IAD to MUC direct, and who is also unvaxxed had no problem with just showing a negative test. So my question - was the agent correct to refuse my colleague boarding?