It's also sending parents to Hong Kong to seek vaccinations by foreign drug companies, dealing another setback for China's US$122 billion drug industry, which has been dogged with concerns over safety. The stocks of many Chinese drugmakers have plunged as investigations continue, wiping out the equivalent of about US$22 billion in market value since the scandal broke.
The industry is still recovering from a 2016 scandal over expired vaccines being sold nationally.
The reaction from investors and the public have some money managers recalling the tainted milk scandal a decade ago in which at least six babies died and hundreds of thousands of others became sick after consuming locally made infant formula laced with the chemical melamine.
"The vaccine scandal could be more serious and have wider ripple effects than the tainted milk incident," said Wang Chen, a Shanghai-based partner with Xufunds Investment Management Co. "As long as it concerns public health there's no such thing as a small incident."
The fallout in China's pharmaceutical industry has spread beyond vaccine makers. Health-care companies in the Shanghai Shenzhen CSI 300 index have dropped about 9 per cent since Changsheng announced in mid-July it was recalling its rabies vaccine, with none of the 20 stocks traded showing gains during the period.
The Government said about 650,000 child vaccines didn't meet standards. That means they may not offer the children who received them protection from deadly diseases: whooping cough, tetanus and diphtheria.
The news has triggered a surge for children's inoculations in Hong Kong from mainland parents, according to Henry Yeung Chiu Fat, a doctor who's president of the Hong Kong Doctors Union.
Hong Kong Vaccination Station, a private clinic in Kowloon's Tsim Sha Tsui, said appointments for some child immunisations are fully booked in July and August because of a surge in demand. Manna Wang, an insurance agent in Shenzhen, booked 20 vaccination appointments for clients last week, compared to an occasional request before.
Olivia Zhang, a Beijing mother of two, was among those who sought shots in Hong Kong for her children. She made an October appointment for her children to get jabs for meningococcal immunisation in Hong Kong. Her 4-year-old daughter received the Changsheng-produced vaccine in April.
"I will not trust the regulator nor Chinese medicines anymore," said Zhang. "No words can be used to describe my anger when I first read the scandal in news. The safety of children should be society's bottom line."
- Bloomberg