South Africa's COVID-19 vaccine rollout has been hit by further delays after authorities decided to discard at least 2 million Johnson & Johnson vaccines.

In a statement, the South African Health Products Regulatory Authority said they decided not to issue the vaccines, that came from a batch of possibly contaminated doses.

This is the latest setback to South Africa's vaccine rollout which has so far given shots to just over 1 percent of its 60 million people.

The vaccines were found by the U.S Food and Drug Administration to be unsuitable for use due to possible contamination of their ingredients at a Baltimore plant.

The production of the J&J vaccine at South Africa's Aspen Pharmacare manufacturing plant in the eastern city of Gqeberha, formerly known as Port Elizabeth, was eagerly awaited to give a much-needed boost to the country's vaccination drive.