Greta Thunberg, the 17-year-old Swedish climate activist, urged young people to stay home after announcing she likely had the coronavirus disease COVID-19. The 17-year-old posted a lengthy caption on Instagram explaining her symptoms and course of action even though she did not get a chance to get tested – “In Sweden you can not test yourself for COVID-19 unless you’re in need of emergent medical treatment.” “Many (especially young people) might not notice any symptoms at all, or very mild symptoms,” she said on Instagram, where she has 10 million followers. “Then they don’t know they have the virus and can pass it on to people in risk groups.” “We who don’t belong to a risk group have an enormous responsibility, our actions can be the difference between life and death for many others,” she said. Ms. Thunberg spoke to European Union lawmakers at a meeting in Brussels in early March. In an effort to protect her mother and her sister at home in Stockholm, Ms. Thunberg said she and her father, who accompanies her on her travels, had isolated themselves in a separate apartment. “This it what makes it so much more dangerous. Many (especially young people) might not notice any symptoms at all, or very mild symptoms. Then they don’t know they have the virus and can pass it on to people in risk groups,” she explained. “We who don’t belong to a risk group have an enormous responsibility, our actions can be the difference between life and death for many others,” urged Thunberg. The young Swedish activist has been a vocal advocate for climate change and landed on the 2019 TIME 100 List as one of the most influential people in the world.