On December 1, Charité — Universitätsmedizin Berlin reported new findings on the origins of the SARS-CoV-2 variant Omicron, one of which was a “stepwise” emergence of the variant across Africa rather than the accepted scenario of it emerging in a single area around South Africa.
In light of new findings of contaminated samples used in the research, the team led by Prof Jan Felix Drexler has now retracted the article, which was published in the journal Science.
The new findings mean that some of the article’s statements are no longer provable beyond reasonable doubt, and the authors retracted their article in line with sound scientific procedure.
In the article entitled “Gradual emergence followed by exponential spread of the SARS-CoV-2 Omicron variant in Africa”, researchers came to the conclusion that the Omicron variant of SARS-CoV-2 emerged in western Africa a few months prior its eventual discovery in South Africa in early November. Shortly after the article was published, other scientists, such as SA’s Dr Tulio de Oliveira, called into question the plausibility of the genome sequences analysed in the study. Subsequent analysis of residual samples found evidence of contamination, the source of which can no longer be traced.
One of the article’s messages — that viruses with Omicron sequence signatures existed across the continent before Omicron was officially detected in South Africa — is based on collective data from PCR analysis done independently by laboratories in several African countries. However, the conclusive reconstruction of the virus’s evolution, another of the article’s key messages, is likely to be affected by sequence contamination not detected before analysis.
The contamination also makes it impossible to correct the analyses retrospectively in due time, because this would require additional analyses of thousands of patient samples from Africa that may not be available in sufficient quantity and quality. Therefore, in agreement with all the authors, the entire article is being retracted. The research group that ran the project is currently carrying out an evaluation and review of the analyses.
Prof Drexler and his team expressed regret for the incident and gratitude to their international colleagues for flagging the potential problems following the article’s publication.
