Prof Veronica Ueckermann of UP’s Department of Internal Medicine offers insight into the latest COVID-19 subvariant, XBB.1.5 or “Kraken”, and its implications for the foreseeable future.

In the wake of the past three years, people the world over are understandably fatigued by mere mention of the COVID-19 pandemic. So the announcement of yet another variant, although expected, is certainly unwelcome.

The XBB.1.5 variant – dubbed the “Kraken” – is currently the dominant variant in the US, and has been dubbed by the World Health Organisation as the “most transmissible variant to date”. Recently, it was detected in South Africa and sequenced by a team in Stellenbosch. 

It is a sublineage of the Omicron variant, which had been circulating in South Africa as the dominant strain in 2022. It is not yet known whether XBB.1.5 will behave differently from other Omicron sublineages that we have seen.

The emergence of new variants is to be expected – it is a means by which viruses evade immune responses in human hosts and continue to survive. With any emerging variant, there are two things we need to know: its transmissibility (how contagious it is and how rapidly it is likely to spread) and the severity of disease it causes.

XBB.1.5 is highly transmissible, which means it’s likely to spread quite rapidly. This is being seen around the world, with more than 29 countries having reported the variant. The US has seen an increase in hospitalisations, though it’s important that this be interpreted in light of rising hospital admissions for respiratory infections that generally occur during winter.  

To date, it is unclear whether the increased number of cases of COVID-19 translates to increased mortality in other countries. South Africa has not seen an increase in hospitalisations, severe disease or COVID-19-related deaths.

The symptoms of XBB.1.5 are not different from previous variants, and range from people having hardly any symptoms all to mild flu-like symptoms, to more severe shortness of breath and pneumonia. For mild disease, only symptomatic treatment is required. 

In South Africa, there has been widespread circulation of Omicron sublineages; this means the country has a high population immunity and might not see a large increase in infections. South Africa also has an excellent genomic surveillance network – which includes a team from UP – and efforts have been intensified to track the growth of XBB.1.5. 

Information is frequently updated on the website of the National Institute for Communicable Diseases, which will be an important and reliable source of information as the trajectory of the new variant unfolds.   

For the moment, no additional public health responses have been put in place and no safety restrictions have been reinstated. The Department of Health has encouraged people to get their SARS-CoV-2 vaccinations and boosters, as, based on previous variants, there is evidence that vaccination reduces the risk of severe disease, hospitalisation and death. This is especially true for vulnerable demographics such as the elderly.  

If you are concerned about symptoms, be sure to discuss them with your healthcare practitioner.