The BA.4 and BA.5 strains of omicron – which appear to be very much like the original strain of omicron – make up the majority of the new cases, according to Professor Marta Nunes, a researcher at Vaccine and Infectious Diseases Analytics at Chris Hani Baragwanath Hospital.
“The majority of new cases are from these two strains. They are still omicron … but just genomically somewhat different,” she told The Associated Press, noting that there is a small increase in hospitalizations and “really very few deaths.”
The average of new cases have risen from around 300 per day in April to about 8,000 per day last week – though experts posit that the actual number of cases is much higher. The sub-variants appear to infect people who have immunity from earlier COVID-19 infections and vaccinations, and Nunes said they cause generally mild disease.