Discovery's vaccine site at its head office in Sandton temporarily implemented walk-ins on Wednesday - this following a scheduling glitch.
The financial services provider earlier issued a statement indicating that the vaccination centre will revert to scheduled visits on the Electronic Vaccination Data System (EVDS) from Thursday.
"The temporary walk-ins only applied today. This was to ensure that not a single day is lost in vaccinating the nation," said Discovery Health CEO Ryan Noach.
"We return to EVDS bookings again from tomorrow, Thursday 20 May. EVDS is scheduling and allocating vaccines efficiently, and we're working closely with the Department of Health team to vaccinate the scheduled recipients. We continue to encourage everyone over 60 to register and come forward for their vaccine when invited to do so," he added.
The site can no longer accommodate further walk-ins for Wednesday.
Discovery started providing jabs on Monday, as Phase 2 of the vaccination programme launched.
Apart from its head office, other sites where it is administering vaccines include Virgin Active Clubs and Gallagher Estate.
Those over 60 are encouraged to register on the EVDS, in order to to be scheduled for a vaccination time, date and site.