Health authorities have launched an investigation after 14 people in Hong Kong were given expired Covid-19 vaccines at a private medical chain.

The Department of Health found after a routine check on Wednesday that BioNTech’s bivalent vaccines which had been kept between one to eight days after the suggested use by date were used on patients from March 21 to March 28 at the Kowloon Bay branch of Quality HealthCare.

Vaccine maker Fosun Pharma had suggested that the jabs should be kept at between two to eight degrees Celsius (35.6 to 46.4 degrees Fahrenheit) and be used inside 70 days after they were thawed out, the department said on Wednesday night.

The department added it had consulted city experts and the vaccine maker about the safety, efficacy and quality of the vaccine and said no re-vaccination was needed for the people affected.

But the authorities said Quality HealthCare should contact the affected patients to explain the situation and follow up on their health.

They said the clinic should deal with reports of discomfort immediately and also notify the department. No reports have been made.