Seventeen-year-old Swedish climate activist Greta Thunberg is in recovery from a likely case of coronavirus.

In an Instagram post, Thunberg announced that she and her father, Svante Thunberg, have been self-isolating since returning from a trip around Central Europe two weeks ago. “I was feeling tired, had shivers, a sore throat, and coughed,” Thunberg wrote. “My dad experienced the same symptoms, but much more intense and with a fever.”

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The last two weeks I’ve stayed inside. When I returned from my trip around Central Europe I isolated myself (in a borrowed apartment away from my mother and sister) since the number of cases of COVID-19 (in Germany for instance) were similar to Italy in the beginning. Around ten days ago I started feeling some symptoms, exactly the same time as my father – who traveled with me from Brussels. I was feeling tired, had shivers, a sore throat and coughed. My dad experienced the same symptoms, but much more intense and with a fever. In Sweden you can not test yourself for COVID-19 unless you’re in need of emergent medical treatment. Everyone feeling ill are told to stay at home and isolate themselves. I have therefore not been tested for COVID-19, but it’s extremely likely that I’ve had it, given the combined symptoms and circumstances. Now I’ve basically recovered, but – AND THIS IS THE BOTTOM LINE: I almost didn’t feel ill. My last cold was much worse than this! Had it not been for someone else having the virus simultainously I might not even have suspected anything. Then I would just have thought I was feeling unusually tired with a bit of a cough. And 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. 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. Please keep that in mind, follow the advice from experts and your local authorities and #StayAtHome to slow the spread of the virus. And remember to always take care of each other and help those in need. #COVID #flattenthecurve

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Although Thunberg and her father have yet to be tested — coronavirus testing is limited in Sweden to those requiring urgent medical care — she noted that “it’s extremely likely that I’ve had it, given the combined symptoms and circumstances.”

Thunberg began her rise to international fame in August 2018, when she began skipping school every Friday to protest inaction on climate change outside the Swedish parliament. Since then, she has spoken at global climate meetings in Poland and Spain, and traveled around the world (sometimes by zero-emissions sailboat) to join other youth activists pushing for policy change.

The global pandemic hasn’t stopped the progress of her movement, Fridays for Future, although it has moved youth activism online for the time being. On March 13 (week 82 of her own school strike), Thunberg asked fellow activists to join her online for a #DigitalStrike — many did so, posting pictures of themselves at home with signs reading “Stop Fossil Fools” and “There Is No Planet B.”

Thunberg’s advice about the novel coronavirus is the same as her advice about climate change: Listen to the scientists. “Had it not been for someone else having the virus simultainously [sic] I might not even have suspected anything,” she wrote on Instagram, warning that young people might not know that they are ill.

“Follow the advice from experts and your local authorities and #StayAtHome to slow the spread of the virus.”