A recent South African laboratory study using Covid-19 samples from an immunosuppressed individual has showed that the virus evolved to become more pathogenic, reported Bloomberg on 26 November.

The study, that used Covid-19 samples over six months, indicated that a new variant could cause more illness than the current predominant omicron strain.

Last year, the same South African laboratory was to first test the omicron strain against vaccines. It now has used samples from a person infected with HIV.

In the past 6 months, the virus initially caused the same level of cell fusion and death as the omicron BA.1 strain, but as it evolved those levels rose to become similar to the first version of Covid-19 identified in Wuhan in China.

Led by Dr. Alex Sigal at the Africa Health Research Institute in Durban, South Africa, the study showed that if the Covid-19 pathogen continues to mutate, a new variant could become even more life-threatening than it is currently.

However, the study is yet to be peer reviewed and is based solely on laboratory work on samples from one individual.

Previously, Sigal and other scientists have postulated that variants such as beta and omicron -- both initially identified in southern Africa -- may have evolved in immunosuppressed people such as those infected with HIV.

The long time it takes for these individuals to shake off the disease allows it to mutate and become better at evading antibodies, Bloomberg quoted the researchers have said.

"The study may indicate that SARS-CoV-2 evolution in long-term infection does not have to result in attenuation," the researchers said in their findings, which were released on Nov. 24.

“It may indicate that a future variant could be more pathogenic than currently circulating Omicron strains," it added.