The World Health Organization on Friday approved the emergency listing of Johnson & Johnson’s COVID-19 vaccine developed by Janssen, the European subsidiary of the American firm.

The WHO said abundant clinical data shows the one-dose regimen is also effective for elderly people.

The Janssen vaccine needs to be stored at minus 20 degrees Celsius but can be kept in temperatures of two to eight degrees for three months. Its shelf life is two years.

The WHO approval follows the European Medicines Agency's authorization announcement on Thursday.

The COVAX Facility global vaccine program has signed an agreement for more than 500 million doses of the Janssen vaccine.

South Korea has procured doses for six million people.