A South African laboratory study using a Covid-19 sample from an immunosuppressed person for six months found that the virus had become more pathogenic, indicating that a new variant could be a reason for illness than the current predominant omicron strain.
The study, conducted by the same laboratory that first tested the Omicron strain against the vaccine last year, used samples from a person infected with HIV. Over six months the virus initially caused similar levels of cell fusion and death as the Omicron BA.1 strain, but as it evolved these levels became similar to the first version of Covid-19 identified in Wuhan, China.
The study, led by Alex Segal of the Africa Health Research Institute in Durban, South Africa, indicates that the Covid-19 pathogen may mutate and a new variant may be a reason for more severe illness and death than the relatively mild Omicron strain. The research has not yet been peer-reviewed and is based on laboratory work on only one individual sample.
Sigal and other scientists previously hypothesized that variants like beta and omicron — both initially identified in South Africa — could develop in immunosuppressed people, such as those infected with HIV. The longer it takes for these people to get rid of the disease allows it to mutate and become better at evading the antibodies, they said.
The study “may indicate that long-term infection does not necessarily result in SARS-CoV-2 evolution,” the researchers said in their findings, which were published on November 24. “This may indicate that a future variant may be more pathogenic than the currently circulating Omicron strain.”