Omicron BA.4, BA.5 is more…: Epidemiologist on new strains as Covid surges in South Africa

The new omicron sublineages - BA.4 and BA.5, which were discovered by South African earlier this month, account for about 70% of new coronavirus cases. And experts suggest that it appears to be more infectious than previous strains.

The BA.4 and BA.5 sublineages appear to be more infectious than the earlier BA.2 lineage, which itself was more infectious than the original omicron variant, Tulio de Oliveira, who runs gene sequencing institutes in the country, said on Twitter.

“Our main scenario for Omicron BA.4 and BA.5 is that it increases infections but that does not translate into large hospitalizations and deaths,” he said in a series of Tweets.

Oliveira had earlier notified that the lineages have not caused a spike in infections in South Africa. So far, the subvariants have been detected in South Africa, Botswana, Belgium, Germany, Denmark, and U.K.

“Given the very low infections, hospitalizations and deaths in South Africa we are alerted about the continued evolution but not concerned," de Oliveira said. “All of the laboratory science on virus neutralization and vaccines are already under way and we are strengthening genomic surveillance."

WHO official had pointed out, so far, we haven't detected any changes in the epidemiology or severity of BA.4 or BA.5 compared to previous sub-lineages of Omicron. But this may change!

South Africa yesterday recorded 6,372 new cases with a positivity rate of 21.1%. That compares with 581 cases and a positivity rate of 4.5% on March 28. The National Institute of Communicable Diseases has said hospitalizations and deaths are rising, albeit slowly.