In a paper appearing in the Proceedings of the National Academy of Sciences, the Massachusetts Institute of Technology's Rudolf Jaenisch and his colleagues report that SARS-CoV-2 RNA can sometimes be reverse-transcribed and integrated into the host genome and further be expressed as chimeric transcripts.
But, as Science reports, critics have said that the findings in this and in an earlier version of the analysis posted to BioRxiv are likely due to lab artifacts and that stronger data is needed to support the claim. Jaenisch tells it that the PNAS paper addresses some of the concerns critics brought up after the preprint was posted and argues that lab artifacts cannot account for all the chimeric reads they detected.
One critic, Cornell University's Cedric Feschotte, tells Science that the "integration data in cell culture is much more convincing than what was presented in the preprint, but it's still not totally clean."
Additionally, it's unclear whether this finding has clinical implications, Science says. In their paper, Jaenisch and his colleagues suggest that their finding could explain why some people produce SARS-CoV-2 RNA even after they recover, though Feschotte notes at Science that the virus could be able to persist in patients for months without integration.