Editorial Retraction.

Abstract

In the Research Article “Gradual emergence followed by exponential spread of the SARS-CoV-2 Omicron variant in Africa”(1), we reported data from retrospective characterization of viral genomes of putative ancestors of the SARS-CoV-2 Omicron variant from western Africa months before the first detection of Omicron. After several social media posts suggested that these putative early Omicron ancestor sequences may have been false positives, we reanalyzed our data and the residual samples. We found a mixture of different SARS-CoV-2 genomic fragments contaminating some of the samples and sequence data on which we based our analysis. The residual samples are now exhausted, and the reconstruction of evolutionary intermediates cannot be replicated. Therefore, we are retracting our Research Article. The epidemiological data are not called into question and will be made available.