Changsheng’s vaccines have not yet been tied to any deaths or illnesses, but the story caught on because it so perfectly echoed many scandals that have rocked China in recent years. In 2016, for example, a hospital pharmacist sold two million doses of vaccines improperly stored in an “overheated, dilapidated storeroom.” That came after scandals over tainted milk, infant formula, pork, cooking oil, and water. The scandals, one after another, have undermined trust in the government’s ability to keep the public safe.

“People in leadership aren’t doing their best by the people,” one user commented on Weibo, a Twitter-like Chinese social network. “It’s a series of scandals about fake baby formula, fake vaccines, child abuse in daycares, sexual assault ... everything we eat, wear, and use endangers us.”

“My children already drink imported baby formula, now they need to start getting imported vaccines,” said another Weibo user. “Might as well leave the country for all our health needs.” Since 2008, when formula tainted with the chemical melamine killed six babies and sickened 300,000 more, Chinese parents have been wary of domestic formula. Those who can go to Hong Kong to buy infant formula. And since news of the faulty vaccines broke, clinics in Hong Kong have been fielding calls from panicked parents in mainland China. One Hong Kong clinic told the South China Morning Post that its phone had been ringing nonstop.

By Tuesday, Weibo users had viewed hashtags related to the vaccine scandal more than 600 million times, according to The Guardian. A Weibo post from the state-run newspaper People’s Daily urged calm over the matter. “Don’t spread panic and anger. Relevant departments must respond in a timely manner with updates,” read the headline.

The now-deleted WeChat post—which still lives on in parts of the internet, such as on the Ethereum blockchain—was not restrained. In a conspiratorial tone, it spins a long, complicated tale of shareholders, eye-popping profits, mistresses, and more. At times, the language is unflinchingly direct: “Experts at the Peking University Health Science Center summarized the act of injecting the ineffective vaccines in people in one word: murder.” And it made the story viscerally relevant to readers: “The vaccines they produce are flowing every day into you and your child’s bodies.”

WeChat is ubiquitous in Chinese life, and it has become a major and decentralized source of news in China. (The app is essentially a messaging app, but it has features of Facebook, iMessage, Instagram, Venmo and Skype all rolled into one.) Columbia Journalism Review recently highlighted how the platform has enabled the rise of independent writers untethered to legacy media outlets. But it has also enabled a type of news that thrives on social media. “Heavy on emotion and light on accuracy, the most-read and shared stories on the WeChat platform are often selective with details,” writes Mia Shuang Li in CJR. Hoaxes such as stories about foods causing cancer flourish on the platform. Fake news on WeChat is such a problem that fact-checking sites have also sprung up.