Hong Kong and Macau on Wednesday said they were suspending the use of Pfizer/BioNTech's coronavirus vaccine after being informed of a packaging problem with a batch of vials.
"For the sake of precaution, the current vaccination must be suspended during the period of investigation," Hong Kong's government said in a statement.
Both Chinese cities said their decision came after they were contacted about the issue by Fosun, the Chinese pharmaceutical company that is distributing the Pfizer/BioNTech vaccine in China.
Vials with the lot number 210102 were found to have defective packaging, authorities said.
The statements from Hong Kong and Macau did not give any details on how the packaging was defective but both said they did not believe there were any safety risks.
Authorities said they decided to act out of an abundance of caution until their investigation is concluded.
Some Hong Kongers took to social media to say their appointments that day had been cancelled and that some vaccination centres were closed.
One centre visited by an AFP reporter had been taped off.
