A South African laboratory investigation using COVID-19 samples from an immunocompromised individual over six months revealed that the virus mutated to become more pathogenic, suggesting that a new variety could cause more sickness than the prevalent omicron strain.

HIV-infected individuals' samples were utilized in the study, which was undertaken by the same laboratory that was to test the omicron strain against vaccines for the first time last year. Over six months, the virus initially produced the same degree of cell fusion and death as the omicron BA.1 strain, but as it progressed, those levels climbed to become comparable to the initial variant of COVID-19 discovered in Wuhan, China.

The study, directed by Alex Sigal of the Africa Health Research Institute in Durban, South Africa, suggests that the COVID-19 pathogen may continue to mutate, and a new version may cause more severe sickness and mortality than the comparatively mild omicron strain. The report has not yet been peer-reviewed and is based exclusively on laboratory work with samples from a single person.

Sigal and other researchers have hypothesized that HIV variations such as beta and omicron, which were initially detected in southern Africa, may have evolved among immunocompromised individuals, such as those with HIV. They claim that the length of time it takes for these patients to recover from the sickness permits it to mutate and grow more adept at evading antibodies.

The study "may indicate that SARS-CoV-2 evolution in long-term infection does not necessarily result in attenuation," the researchers noted in Thursday's findings. It may signal that a future variety could be more pathogenic than the Omicron strains now circulating.