The rate of breakthrough infections – when a vaccinated person becomes infected – grew considerably in the fourth wave of Covid-19, which was driven by the Omicron variant.
However, there are significant positives to the fourth wave, including fewer hospital admissions, shorter hospital stays and fewer patients requiring oxygen. The unvaccinated account for the majority of admitted Covid-19 patients.
This is according to the latest data presented by the department of health and the National Institute for Communicable Diseases (NICD) on Friday.
South African has seen a considerable rise in breakthrough infections.
SA Medical Research Council CEO Prof Glenda Gray said, during the Omicron wave, 29 282 breakthrough infections had been reported, compared with 10 625 during the devastating Delta wave and 11 586 during Beta.
Daily infections during the fourth wave, driven by the Omicron variant, were three times those recorded during the previous wave.
However, Dr Waasila Jassat, public health specialist at the NICD, explained that, compared with previous waves, which spanned at least two or three months, “this wave was very tight”.
The number of Covid-19 patients who passed away in hospital was also considerably lower during the Omicron wave.
“The proportion of admitted patients who died in hospital was 9.7% compared with 21.5% in the first wave, 28.8% in the second wave and 26.4% in the third,” Jassat revealed.
Data for 26% of admitted Covid-19 patients reflects that 82% were unvaccinated.
Analysing data for 32% of Covid-19 related deaths, Jassat confirmed that 82% of these patients had not been vaccinated.
Omicron remains the dominant variant
Other Covid-19 variants are barely being detected in South Africa any longer. Dr Michelle Groome, the head of the division of public health surveillance and response at the NICD, said sequencing showed that almost 99% of the variants detected were Omicron.
“You can see how rapidly this variant has overtaken the others, with very, very low proportions of the others detected at the moment.”
There was concern about the infection rate among children, but Groome said the under 10-year-old category remains the one with the lowest incidence.
There was an increased incidence among 20- to 39-year-olds in the fourth wave. The elderly saw a decline in incidence, which Dr Groome said could be attributed to the fact that vaccinations were highest among this age group.
There has been an almost 5% reduction in reported deaths over the past seven days and, as of Thursday, a 27% reduction in new cases compared with seven days before.
South Africa recorded an almost 14% reduction in new Covid-19 cases in the first week of January.
In the past week, the Western Cape accounted for the highest number of new cases, followed by KwaZulu-Natal and Gauteng. The other provinces accounted for only 11% of new cases.