South Africa: Race On to Study New Mutations As Omicron Ba.4 and Ba.5 Likely Cause of 5,000 New SA Covid Cases Overnight

The number of coronavirus infections in South Africa jumped by 5,000 on Tuesday 26 April 2022, with a slight drop in the positivity rate to 18%. Experts say they believe sub-lineages of the Omicron variant are responsible for the current spike in cases. Now, the race is on for them to understand how BA.4 and BA.5 are evading immunity due to prior infection and vaccination.

While most new cases of coronavirus infections are still registered in Gauteng and KwaZulu-Natal, Dr Nicole Wolter of the National Institute for Communicable Diseases said two of the sub-lineages of the Omicron variant – known as BA.4 and BA.5 – have different mutations to other Omicron sub-lineages.

This might indicate that these lineages can escape some of the body’s immune defences, Wolter said, adding that this could lead to an increase in the number of Covid cases and potentially a fifth wave.

“The Network for Genomic Surveillance in South Africa continues to closely monitor SARS-CoV-2 variants and sub-lineages circulating in SA. Work is also ongoing to determine the impact of the BA.4 and BA.5 mutations on the virus,” she added.

Wolter said an increase in the number of Covid cases and the proportion of cases…