The Chinese government is turning to censorship and appeals for calm, amid mounting public anger following revelations earlier this week that one of the country's largest vaccine makers had violated safety standards.
Furor about the faulty vaccines, an estimated 250,000 of which may have been administrated to children, has continued to dominate Chinese social media, further eroding public trust in essential services.
There are also suggestions the scandal could affect China's standing overseas as the country tries to position itself as a major player in the global pharmaceutical industry.
On Tuesday, the chairperson of the company at the center of the scandal, Gao Junfang of Changchun Changsheng Biotechnology, was detained, along with 14 other people involved in the case, according to an official police statement.
The swift actions of the police have so far done little to quell the outcry. Outside the Capital Institute of Pediatrics in Beijing, one of the country's premier children's hospitals, one parent told CNN the company had "no conscience" and the government needed to regulate more strictly.
Another parent, Peng Yubin, said he was considering using foreign vaccines for his child. "Even though they are more expensive, they are better," he said.
Several days on from the initial news, there is still no official information regarding how many children may have been injected with the questionable vaccines or what effect they may have.
In an article published Tuesday, state-owned China Daily quoted experts calling for "a rational attitude" towards immunization, saying the faulty diphtheria and tetanus vaccines (DPT) "won't harm people's health." Similarly, the official newspaper of the Communist Party, the People's Daily, ran an interview with an expert alleging the vaccines were "safe," just ineffective. Evidence in support of these claims has yet to be provided by authorities.
On Monday evening, State Drug Administration Deputy Director Xu Jinghe appeared on state-owned CCTV in an attempt to calm public concerns, but the footage provoked scorn, with social media users mocking Xu's expensive, blue Burberry polo shirt and stilted answers.
One Weibo user reprimanded Xu for his choice of clothes: "Improper dressing for such an occasion." "The people are fed up with you!" another user posted.
Government censors had initially allowed public discussion. However, by Wednesday, attempts were underway to control the flow of information, with the word "vaccine" among the most restricted on China's social media platform Weibo, according to the Journalism and Media Studies Centre at the University of Hong Kong.
Numerous essays and top rated comments were scrubbed from online platforms, including a widely shared article titled "King of Vaccine," which accused the owner of Changsheng of corruption and unethical behavior.
There is growing evidence the scandal could spill beyond China's borders, impacting the country's long held ambition to become a major player in the global pharmaceutical industry.
"The Changchun Changsheng scandal jeopardizes Beijing's efforts to push domestically made pharmaceuticals on the international market," wrote Viola Rothschild, a research associate in Asia Studies at the Council on Foreign Relations, in a blog posted Tuesday.
"Under China's 'Made in China 2025' plan, pharmaceuticals are a target industry: President Xi has identified China's reliance on imported drugs as an issue that can be resolved by overhauling the pharmaceutical industry and ultimately creating globally competitive firms," said Rothschild.
In Changchun Changsheng's 2017 annual report, which it filed to the Shenzhen Stock Exchange, the company claimed to have sold products to "more than ten countries like India, Cambodia, Nigeria, Egypt, Belarus and some other European, African, Middle Eastern and South American countries."
According to the report, Changchun Changsheng sold more than 36 million yuan ($5.28 million) worth of goods overseas in 2017.
There is no indication that the defected vaccines were among those shipped to other countries. CNN has contacted health ministries of the countries listed in the annual report for comment.
"Chinese manufacturers (across all sectors) have worked hard to shake the conception that 'Made in China' is synonymous with 'low quality,' but incidents like these undermine trust and are a reminder that despite recent reforms and advancements, safety and testing requirements in China are not up to international standards," said Rothschild.
Chinese Ministry of Foreign Affairs spokesman Geng Shuang said questions about tainted vaccines being shipped internationally were not a matter for his ministry at his daily briefing on Tuesday.
Hundreds of thousands potentially affected
The crisis began when more than 250,000 doses of Changchun Changsheng's diphtheria and tetanus (DPT) vaccine were found to be faulty, according to the Jilin Provincial Food and Drug Administration.
The vaccine is part of the national mandatory program and an unconfirmed number of children have been given the questionable drugs, authorities said, provoking widespread outrage and concern.
Another 113,000 doses of Changsheng's rabies vaccine were also affected, according to authorities.
The controversy is just the latest in a series of public scandals around Chinese goods and medicines.
In 2008, baby formula produced and fed to infants in China was discovered to be tainted with melamine, a chemical compound mainly for industrial use, affecting tens of thousands of children and provoking widespread panic.
Anxious parents emptied supermarket shelves in Hong Kong, Australia and New Zealand, among other places, in their search for safe milk formula for their infants.
It isn't even the first vaccine scandal China has faced -- in 2016, a criminal organization was found to be selling millions of improperly stored vaccines, which had been widely disseminated.