New research on the COVID-19 Omicron subvariant BA.5 has suggested the virus could be changing how it infects the human body - by targeting the brain.
Researchers from Australia and France found the coronavirus subvariant did much more severe damage to the mouse and human brain tissues they tested on, compared with the BA.1 subvariant.
The researchers found the BA.5 subvariant lead to brain inflammation, weight loss and death.
"Compared with BA.1 we found that a BA.5 isolate displayed increased pathogenicity in K18-hACE2 mice with rapid weight loss, brain infection and encephalitis, and mortality. In addition, BA.5 productively infected human brain organoids significantly better than BA.1," a manuscript from the research said.
However, virologist Jin Dongyan argued the study had a major setback as it was tested on the brains of mice and the infections likely wouldn't happen to humans.
"They showed that all the mice died from brain infections of BA. 5, which is apparently very different from human infections that we know of," Dongyan told the South China Morning Post.
Dongyan added the World Health Organization has said the pathogenicity of Omicron variants had not increased, despite the increase in subvariants.
