December 15, 2021 - 3:00pm

Since its discovery in the Gauteng province of South Africa in November, a new Covid variant has set off a spiral of harsh restrictions, travel bans and questions about the efficacy of the existing two-dose vaccines. Dr Angelique Coetzee, the scientist who first raised the alarm in Gauteng, has repeatedly assured the public that early observation of symptoms suggests that Omicron could be milder than the Delta variant. Despite some reassuring signs on the ground, reaction to the new variant has been dramatic, with Boris Johnson warning of a ‘tidal wave’ of cases in the UK and Joe Biden predicting an ‘explosion’ of cases in the US.  

To unpick some of the data coming out of Gauteng, Freddie Sayers sat down with researcher at the University of Johannesburg, Pieter Streicher, who has been following the developments of the Omicron variant in his home country. 

Pieter is clear that, like all waves of the virus, there will predictably be a sharp increase in cases in the coming weeks in South Africa and beyond. But cases are not, he says, the best metric by which to measure the threat of Omicron. When measuring the virulence of any variant, it is more important to study records of hospitalisations and excess deaths. 

By these measures, Omicron is resulting in hospital admissions well below the previous wave in South Africa, and needing far less interventions like ventilation or supplemental oxygen. Excess deaths look likely to follow this pattern. With Delta, Pieter explains, patients were often coming into hospital with low blood oxygen levels and severe symptoms. Reporting from South African hospitals suggests that a higher percentage of positive tests are ‘incidental’ with the Omicron variant, with patients often asymptomatic or unaware that they were harbouring the virus. 

Pieter appreciates that the initial exponential growth rate for Omicron does look dramatic. But scientists ‘make the mistake to project that [exponential growth rate] well into the future, well beyond even a plausible peak date.’ According to his observations, Omicron’s growth rate appears to already be slowing in Gauteng. 

If symptoms are less severe and numbers slowing, could this new variant actually be good news? Pieter is cautiously optimistic. If Omicron ‘outcompetes’ the Delta variant, then it could spell the end of the pandemic as we know it, putting coronavirus in the same category of disease as the common cold. Pieter is keeping a close eye on the newer numbers being recorded in Europe, as are we.