I have a friend who is a US citizen who lives in Austria and is not vaccinated. Her son who is vaccinated tested positive at the Munich airport right before his flight home to the US. They wanted the names of everyone that they had been in contact with. He was required to remain in Austria and self isolate until he tested negative. Four days later, he tested negative and was free to leave. Because he had been staying in her home, my friend was required to isolate for the full 10 days even though she did not test positive.