As they take stock of the Omicron variant, scientists say it is not enough to rely on vaccines and booster shots. They need to be combined with common sense and non-pharmaceutical interventions.
The fourth wave of Covid-19 has moved through South Africa at a rate that exceeds its predecessors. An Omicron-driven explosion of cases in early December had scientists in this country and around the world mobilising to answer key questions about the new variant. Just a month later, the state announced that the country seemed to be past the peak of the latest surge.
South Africa is now at the tail-end of the fourth wave, according to Professor Salim Abdool Karim, the director of the Centre for the Aids Programme of Research in South Africa.
“What we have found is that with each wave, the rate at which it goes up is similar to the rate at which it goes down,” said Abdool Karim. “[With] Omicron, the spread of the virus is substantially faster. So, the peak was reached much faster than it took us in the previous waves, and that’s why it’s going to end faster as well.”
While the number of infections is coming down, Dr Angelique Coetzee, chairperson of the South African Medical Association, recommended that South Africans give it another two weeks before they “start to celebrate”. “Let’s see what the schools do with the opening,” she said.
The vast majority of cases in recent weeks have been driven by the Omicron variant, with genomic sequencing results released by the Network for Genomic Surveillance in South Africa showing that 83.5% and 98.7% of sequenced Covid-19 samples were Omicron in November and December 2021, respectively.
A defining characteristic of the fourth wave has been the “uncoupling or delinkage” between cases, deaths and hospital admissions in South Africa, according to Professor Glenda Gray, president and CEO of the South African Medical Research Council.
“In the previous waves, cases, hospitalisations and deaths kind of went up together, but in Omicron there were far more cases, and far less deaths and hospitalisations,” said Gray.
This trend was captured in a Lancet preprint paper, released on 29 December 2021, examining patients admitted to hospitals in Gauteng during the fourth wave. The researchers analysed the first four weeks of wave two, three and four in Gauteng, dominated by the Beta, Delta and Omicron variants, respectively.