More than 100 children in eastern China have been given expired polio vaccines by a local health centre, according to mainland media, just months after a public health scare over faulty products.
A total of 145 infants and toddlers in Jinhu county, coastal Jiangsu province received the oral vaccines that were past their expiry date of December 11, news website Thepaper.cn reported.
The case came to light on Monday, when a hospital worker discovered the vaccine about to be given to their child was nearly a month out of date.
Children who have been given the batch of expired vaccines range in age from three months to four years, according to the report.
The report said some of the children had experienced adverse health effects such as vomiting and drowsiness since they were vaccinated.
Jinhu authorities had invited provincial experts to carry out health checks for all affected children on Thursday, the report said, citing the county propaganda chief.
Three public health officials in the county have been removed from their posts and the health centre workers involved have been suspended and placed under investigation, according to the report.
In China, polio vaccines are part of a compulsory immunisation programme provided free by the disease control authorities. Every child must be vaccinated four times from when they are two months until they are four years old.
Confidence in the country's vaccination industry was already low - the Jinhu case comes after a nationwide outcry over vaccine safety last summer that was widely seen as China's worst public health storm in years.
That crisis erupted in July, when the drug regulator reported that Changchun Changsheng Bio-technology, one of the country's biggest vaccine makers, had produced 252,600 substandard DPT vaccines that were given to hundreds of thousands of babies - some as young as three months old.
As well as the faulty diphtheria, whooping cough and tetanus shots, the company also forged data in the production of some 113,000 rabies vaccines, the authorities said. A subsequent investigation found that the company had engaged in such malpractice for more than four years.
It came after health authorities in 2016 said two million improperly stored vaccines had been sold across China. A year earlier, hundreds of infants in central Henan province were reportedly given expired vaccines, causing two deaths. And in 2010, journalist Wang Keqin published investigative reports on unrefrigerated vaccines in Shanxi province that killed four children and sickened more than 70 others.
This article was first published in South China Morning Post.