President Donald Trump didn’t take the advice. On March 16, 2020, he first tweeted the phrase “Chinese virus.”

That single tweet, researchers later found, fueled exactly the kind of backlash the WHO had feared: It was followed by an avalanche of tweets using the hashtag #chinesevirus, among other anti-Asian phrases.

“The week before Trump’s tweet the dominant term [on Twitter] was #covid-19,” Yulin Hswen, an epidemiology professor at the University of California San Francisco and a co-author of the study told The Washington Post. “The week after his tweet, it was #chinesevirus.”…

Not only did more people use the #chinesevirus hashtag days after Trump’s tweet, but those who did were more likely to include other anti-Asian hashtags in their tweets, according to the peer-reviewed study published by the American Journal of Public Health on Thursday.