Publication Date: Tuesday, March 23, 2021
Daniel Lule Bugembe, My V.T.Phan, Isaac Ssewanyana, Patrick Semanda, Hellen Nansumba, Beatrice Dhaala, Susan Nabadda, Áine Niamh O’Toole, Andrew Rambaut, Pontiano Kaleebu, Matthew Cotten

SARS-CoV-2 genomic surveillance in Uganda provides an opportunity to provide a focused description of the virus evolution in a small landlocked East African country. Here we show a recent shift in the local epidemic with a newly emerging lineage A.23 evolving into A.23.1 which is now dominating the Uganda cases and has spread to 26 other countries. Although the precise changes in A.23.1 as it has adapted are different from the changes in the variants of concern (VOC), the evolution shows convergence on a similar set of proteins. The A.23.1 spike protein coding region has accumulated changes that resemble many of the changes seen in VOC including a change at position 613, a change in the furin cleavage site that extends the basic amino acid motif, and multiple changes in the immunogenic N-terminal domain. In addition, the A.23.1lineage encodes changes in non-spike proteins that other VOC show (nsp6, ORF8 and ORF9). The clinical impact of the A.23.1 variant is not yet clear, however it is essential to continue careful monitoring of this variant, as well as rapid assessment of the consequences of the spike protein changes for vaccine efficacy.