South Africa: BA.4 and BA.5 increasing as a proportion of sequenced cases *1 UPDATE*

Africa, BA.4, BA.5, Coronavirus, Deaths, Genome, Health, Healthcare, Hospitalization, Infection, Omicron, Recombination, South Africa, Testing, Transmission

An increasing share of South Africa’s Covid-19 cases are the BA.4 and BA.5 sub-lineages of the Omicron variant, suggesting those might have a growth advantage over others, Prof Helen Rees said on Thursday.

Rees added at a World Health Organisation news conference that despite rising Covid-19 infections, SA was so far not seeing a huge increase in mortality or intensive care admissions.

The WHO said earlier that Africa is seeing an uptick in Covid-19 cases largely driven by a doubling in cases reported in SA.


South Africa has recently issued a document outlining the latest information on BA.4 and BA.5:

Full South African document:




There’s also a new preprint from South Africa researchers at CERI too: “Continued Emergence and Evolution of Omicron in South Africa: New BA.4 and BA.5  lineages”:

“..the continued discovery of genetically diverse Omicron lineages shifts the level of support for hypotheses regarding their origin, from an unsampled location to a discrete reservoir, such as human chronic infections (or even a network of chronic human infections) and/or animal reservoirs, potentially contributing to further evolution and dispersal of the virus. We are actively investigating the potential of a yet unidentified animal reservoir in the region..”







A good thread from German virologist Christian Drosten about BA.4 and BA.5 here (in German):


The Sigall Lab have been doing some research on the immunity gained from infection by BA.1 against reinfection by BA.4 and BA.5.  It’s not good news:


South Africa is currently seeing an increase in Covid cases associated with BA.4 and BA.5:


There has been an uptick in hospitalizations recently too:


South Africa may be entering a fifth COVID wave earlier than expected after a sustained rise in infections over the past 14 days that seems to be driven by the BA.4 and BA.5 Omicron sub-variants, health officials and scientists said on Friday.

Reuters report



UPDATE 1 – 3rd May 2022

“We have entered the 5th wave..”




** This post was originally published on April 29, 2022 **