A decision by South Korean health authorities to allow more doses to be extracted from coronavirus vaccine vials has sparked controversy as the country ramped up its vaccinations of healthcare workers and the elderly.

The Korea Disease Control and Prevention Agency (KDCA) had allowed healthcare workers to use the remaining doses if they can squeeze more out of each vial with low dead space syringes, which minimise the amount of vaccine left in the syringe after use, according to Reuters.

While offering discretion over the use of remaining doses, KDCA made clear the authorities will not make the extraction of the extra doses a new standard or mandatory as it can burden the healthcare workers on site.