Health authorities have warned South Africa may be entering a fifth wave of infections driven by the BA.4 and BA.5 Omicron sub-variants.
South Africa has recorded the most coronavirus cases and deaths on the African continent and only exited a fourth wave in January.
Experts had predicted a fifth wave could start during the southern hemisphere winter months, sometime in May or June.
Just under 50% of South Africa's adult population of roughly 40 million have received at least one dose of Covid-19 vaccine, with 45% of adults fully vaccinated.
The pace of vaccinations has slowed in recent months, with officials warning that shots risk being discarded.
Initially the vaccination campaign was dogged by difficulties securing early supplies but later by hesitancy.
(Reporting by Alexander Winning; Editing by Estelle Shirbon)
A Soweto resident walks in front of informative graffiti artwork educating local Soweto residents about the dangers of the coronavirus, Johannesburg, South Africa, on 30 November 2021. (Photo: EPA-EFE/Kim Ludbrook)