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

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....More...

WHO: BA.2 to remain classified as Omicron

Based on available data of transmission, severity, reinfection, diagnostics, therapeutics and impacts of vaccines, the group reinforced that the BA.2 sublineage should continue to be considered a variant of concern and that it should remain classified as Omicron....More...

Preprint: Omicron incompletely escapes immunity induced by the Pfizer vaccine

Laboratory research from South Africa strongly suggests that the SARS-CoV-2 Omicron variant escapes antibody immunity induced by the Pfizer-BioNTech (Comirnaty) vaccine, but that considerable immunity is retained in people who were both vaccinated and previously infected....More...

Preprint: Omicron is the product of extensive evolution that has left no obvious traces of intermediate forms

The Omicron variant identified in Southern Africa in late November 2021 is the product of extensive evolution within an infection context that has so far left no obvious traces of intermediate forms since it diverged from the B.1.1 lineage (presumably at some time in mid to late 2020)....More...