SARS-CoV-2 Unlikely to Insert Genetic Fragments Into Patients’ Genetic Code

(Reuters) – A new study refutes the controversial claim made by researchers last month in The Proceedings of the National Academy of Sciences of the USA that small fragments of genetic instructions from the coronavirus became integrated into the genome of infected cells, in test tube experiments.

In principle, coronavirus RNA generated by such integrated snippets, while probably not harmful, might cause positive COVID-19 PCR tests long after a patient has recovered, the authors of that study said. But when researchers in Australia sought to find signs of SARS-CoV-2 genetic code integrated into the DNA of infected cells, they could not find any, according to a report posted on bioRxiv ahead of peer review.

“This was despite using the same sequencing technology and cell type (as in the PNAS study) and performing substantially more DNA sequencing,” Geoffrey Faulkner of the University of Queensland told Reuters.

The researchers did find copies of hepatitis B virus integrated into liver tissue, and copies of other DNA elements integrated into the cells they experimented with, “suggesting our approach would have found SARS-CoV-2 copies” if they were present, Faulkner said.

His team agrees with others who suggest the PNAS findings may have reflected unintended effects of experimental methods.

“We think SARS-CoV-2 integration into DNA is possible in human cells in lab experiments even if it is likely to be incredibly rare in patients,” Faulkner said.

SOURCE: bioRxiv, online May 30, 2021.

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