Health workers were supposed to get their Johnson and Johnson booster shot from Monday.

But the Department of Health only sent out SMSs with details of the programme to eligible participants on Sunday night.

Around half a million participants qualify for the booster shot.

The department says the health workers will get another message with a link to a consent form once details have been finalised.

It's hoped that data collected from the study will shed more light on whether a booster shot is needed for the general population.

eNCA