The virus that causes COVID-19 can't rewrite our DNA and turn us into "human-viral chimeras" as some scientists have suggested, a new study has found.
In December, a controversial paper by two scientists at the Massachusetts Institute of Technology (MIT) was published online, claiming on rare occasions, a human cell enzyme might accidentally copy some of the virus' RNA genetic code into an infected person's DNA.
The paper was heavily criticised, Science reported, with the authors admitting they needed stronger evidence. In May stem cell biologist Rudolf Jaenisch and gene regulation specialist Richard Young doubled-down on their original claims, publishing the paper in respected journal the Proceedings of the National Academy of Sciences.
“We now have unambiguous evidence that coronavirus sequences can integrate into the genome,” Dr Jaenisch said.
He said it explained why some people still test positive for the virus months after they've recovered from COVID-19 - the tests are picking up the patient's own DNA, which now has traces of the coronavirus' genetic code.
The findings were picked up by the anti-vaccination movement, even though Dr Jaenisch said there was "absolutely no evidence" COVID-19 vaccines - many of which use mRNA to teach the body how to make parts of the coronavirus - did the same.
But now doubt's being cast on the MIT team's research. Prof Geoff Faulkner of the University of Queensland is a computational and molecular biologist who specialises in changes to DNA.
His team found "no evidence" that either the virus or the vaccines can change DNA.
"We looked into their claims that the human cells and machinery turned COVID-19 RNA into DNA, causing permanent mutations," he said.
"We assessed the claims in cells grown in the laboratory, conducted DNA sequencing and found no evidence of COVID-19 in DNA. From a public health point of view, we would say that there are no concerns that the virus or vaccines can be incorporated into human DNA."
Immunologists have long said there's no way the vaccines can change human DNA, since they don't enter the nucleus of the cell where it's kept.
The Queensland team's research was published Friday in journal Cell Reports.
