Greta Thunberg announced via an Instagram post on Watch Cheerleaders Gone Bad XXX MovieTuesday that she and her father had shown symptoms associated with the novel coronavirus, writing that it was "extremely likely" she contracted the virus.

Thunberg, who famously travels without planes to engage in her climate activism, quarantined herself for the last two weeks after returning from a trip around Central Europe, according to her post. She began feeling symptoms "around ten days ago." Her father, who also experienced similar symptoms, found his symptoms to be much more acute.

In Sweden, where Thunberg lives, testing for COVID-19, the official term for the disease caused by the coronavirus, is prioritized for hospitalized patients and those who work in healthcare or elderly care, according to the Public Health Agency of Sweden. The Public Health Agency of Sweden says that anyone ill with flu or cold symptoms should stay at home, and that this group will not be prioritized for testing. Consequently, Thunberg was not tested.

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She writes that she has "basically recovered," and that while experiencing her symptoms she "almost didn't feel ill" — which is exactly what Thunberg wants her followers to understand.

Without her dad experiencing similar symptoms, Thunberg says that she "might not have suspected anything."

She continues: "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."

In the U.S., some young people, like those who packed Florida beaches for spring break, have shown flagrant disregard for the World Health Organization's recommendations. Although young people are less at risk, no one is invulnerable when it comes to COVID-19.

"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."

This isn't the first time that Thunberg asked for young people to unite behind the science (in the context of COVID-19). Prior to her personal announcement, Thunberg also called for climate strikes to move online, stressing that young people practice social distancing for "the best interest of our common society."