In-Depth: Study suggests coronavirus infection could alter our DNA

Coronavirus RNA
Posted at 5:24 PM, May 12, 2021
and last updated 2021-05-13 13:27:36-04

SAN DIEGO (KGTV) -- New research from a team of prominent scientists suggests the pandemic coronavirus doesn’t just hijack our cells; in some cases it can actually alter our DNA.

It’s a controversial claim. When an early version of the research first appeared online in December, many scientists dismissed the evidence as too thin and potentially the result of a faulty experiment. But last week, the team of researchers led by noted MIT biologist Rudolf Jaenisch published new experiments to bolster their hypothesis.

“Beyond doubt, this is not an in vitro artifact anymore,” Jaenisch said in an interview with ABC 10News. “Integration into the genome can occur.”

It all started with patients like Chris Long. After the Michigan resident was hospitalized with COVID in March 2020, the virus just wouldn’t go away.

“I kept developing pneumonia,” Long said.

He experienced COVID-related complications for months and had to be hospitalized a total of nine times.

Each time, he was swabbed for the virus. PCR tests showed he was repeatedly positive for SARS-CoV-2 from March until December 2020. He finally tested negative in February 2021.

Professor Jaenisch and his colleagues wanted to know why some COVID patients test positive for the virus for months, especially those who are not showing signs of viral replication and are not infectious.

They ran some complicated experiments and found that in test tubes, our cells can accidentally convert fragments of the coronavirus’ single-stranded RNA into double-stranded DNA. Then, that genetic code can get saved to the cells’ hard drive: the chromosomes.

This is the kind of thing HIV does intentionally, but it’s not what scientists would expect from this type of virus.

“Would this be with me for the rest of my life?” I asked Jaenisch.

“It really depends on how long the cells survive,” he replied. “Most cells die after infection. So those would not live very long and present.” There might be other cells outside the lungs where altered DNA could persist “for a long time,” but that's all speculation, Jaenisch said.

He and his collaborators have found indirect evidence of these genetic fusions in tissues collected from patients, but they're still looking for a smoking gun: a protein expressed by the altered code that could reveal the clinical impact.

The research raises all kinds of questions that scientists may not be able to answer for some time. Could these DNA changes explain certain COVID long haul complications, like autoimmune disease? Could these changes increase the risk of cancer?

Scientists call the fusion of viral and human genetic code a “chimeric sequence,” a reference to a fire-breathing hybrid monster from Greek mythology.

“It sounds scary and maybe it is scary, but I think it's probably just a big nothing burger,” said UC San Diego virologist Dr. Davey Smith.

Smith points out there still isn’t direct evidence of this genetic integration happening in people. And even if it is, he said there’s a good chance it’s not a big deal.

“If this is true, then other RNA viruses do this all the time. So every time that I catch an RNA virus that's a cold or another coronavirus, a regular one that normally is running around, then this process is happening already,” he said.

He points out that about 10 percent of our entire human genome is made up of the code from ancient viruses passed down through the generations.

Professor Jaenisch agrees; this coronavirus probably isn’t unique. Fragments of other RNA viruses can probably slip into our DNA, he said. We’re just studying SARS-CoV-2 more closely than any other virus.

Some members of the anti-vax community have seized on this MIT study as evidence that the mRNA vaccines could also alter our DNA. Professor Jaenisch stresses the research in no way implies that.

He himself got an mRNA vaccine. “I think it’s a great thing,” he said.