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Twitter is encouraging its more than 4,800 employees around the world to work from home in response to the spread of the coronavirus. It’s one of the most drastic steps taken by any tech company so far in response to the outbreak.

Over the last few days, a number of Silicon Valley companies have been coping with the virus’s incursion into their workforces. Two Amazon employees based in Italy have contracted the coronavirus, and Facebook has reportedly advised its employees to “feel free” to work from home.

But Twitter went a step further on Tuesday.

“Beginning today, we are strongly encouraging all employees globally to work from home if they’re able,” the company said in a blog post. “Our goal is to lower the probability of the spread of the COVID-19 coronavirus for us — and the world around us. We are operating out of an abundance of caution and the utmost dedication to keeping our Tweeps healthy.”

Twitter is also requiring its employees based in Hong Kong, Japan, and South Korea to work from home, which it said in a blog post that it is mandating “due in part to government restrictions.”

The company said that US offices would still be open for employees who feel the need to come in person.

“While this is a big change for us, we have already been moving towards a more distributed workforce that’s increasingly remote,” Twitter said.

Twitter had previously banned “non-critical” business travel, which included the cancellation of CEO Jack Dorsey’s appearance at the South By Southwest conference in Austin later this month.

The virus has already led to precipitous drops in the value of tech stocks; reduced revenue projections from giants like Apple; new travel restrictions on tech employees’ travel to China, where the virus began; and cancellations of the glitzy conferences hosted by companies like Facebook.

There have been 15 confirmed cases of the virus in the United States, according to the Centers for Disease Control and Prevention, including one death in Washington state. Covid-19 is the disease caused by SARS-CoV-2, or the name for the novel coronavirus. The growing number of cases outside of China — in South Korea, the number of cases has jumped to 3,150 — has sparked some alarm as health officials around the world race to contain the coronavirus’s spread.