ATHENS — Greece’s first female president, a former high court judge, was formally sworn in to office Friday, nearly two months after the country’s parliament voted overwhelmingly to elect her. The ceremony for Katerina Sakellaropoulou, 63, took place in an almost empty parliament, as part of measures to prevent the spread of the new coronavirus. Only a handful of officials and a limited number of journalists were present. Greece has shut down schools, universities, cinemas, theaters, gyms and nightclubs, and authorities have warned people to stay home and avoid large gatherings in an effort to contain the outbreak. The ceremony was covered live on state television. After the swearing-in to the largely ceremonial post, Sakellaropoulou placed a wreath at the Tomb of the Unknown Soldier in the square outside parliament, before a presidential honor guard. Despite the warnings about the virus, a small crowd gathered to watch, standing behind a security cordon across the street. The prime minister of Greece, Kyriakos Mitsotakis is the active chief executive. The new president headed the Council of State, the country’s highest administrative court, since 2018. She takes over the five-year presidency from veteran conservative politician Prokopis Pavlopoulos. In a brief speech at the presidential palace, Sakellaropoulou spoke of the battle against the coronavirus and the recent migration crisis as the country’s two main challenges. Greece must continue to adhere to its democratic principles and laws, moving toward “a future of prosperity that will have room for us all,” she said. In a clear reference to neighboring Turkey, Sakellaropoulou said Greece was being called on to “thwart the aggression of those who, using human pain, want to harm our national...