In early April 2022, the routine surveillance conducted by the Network for Genomic Surveillance in South Africa (NGS-SA), led to the discovery of two new Omicron strains, BA.4 and BA.5.

At the centre of these findings was Prof Tulio de Oliveira, whose Centre for Epidemic Response and Innovation (CERI) at Stellenbosch University heads up the NGS-SA.

De Oliveira, who is Professor on Bioinformatics: School for Data Science and Computational Thinking in the Faculty of Science and Faculty of Medicine and Health Sciences at the University, said there was cause for heightened awareness but not concern over the discovery. Researchers expect the virus to keep evolving, which is why, he stressed, it is critical to identify the evolution of the virus as early as possible so one can prepare for a new variant or sub-variant.

According to De Oliveira, the virus may not be “weakening", but it is estimated that a large majority (likely over 90%) of the South African population has some degree of immunity provided by either vaccination and/or prior infections and is not resulting in severe infection. The evolutionary analysis suggests that Omicron is not “continuing" to emerge, but that “all emergence has already happened and now with shifting immune landscape, different sub-lineages have a chance to grow and there could potentially be other sub-lineages yet to be sampled as well as other variants to emerge".

In this article in Nature, De Oliveira expands on the effects of the new lineages which have been gaining ground in South Africa.

• ​Read a profile article on Prof De Oliveira here​