A young South African HIV patient harboured COVID virus for nine months and it developed more than 20 mutations, a study revealed.

The yet to be peer-reviewed study showed that a 22-year-old female with uncontrolled advanced HIV infection was persistently infected with SARS-CoV-2 beta variant for 9 months. As she stopped her HIV treatment, the virus accumulated "more than 20 additional mutations" in her body, said researchers from the Universities of Stellenbosch and KwaZulu-Natal, among others. However, with anti-retroviral therapy, the HIV was "suppressed" and COVID virus was "cleared within 6-9 weeks".

"Increased vigilance is warranted to benefit affected individuals and prevent the emergence of novel SARS-CoV-2 variants," the researchers said. The study demonstrated that COVID-19 may mutate rapidly in those whose immune system is weakened by HIV infection.

It has already been observed that COVID-19 can linger for many months in patients who are HIV positive but who have, for varying reasons, not been taking the medicines that would enable them to lead healthy lives. It is also hypothesised that the emergence of new COVID-19 variants could be linked, in some cases, to untreated HIV.

According to some scientists, it is "highly plausible". Late last year, a South African research team found an untreated HIV patient who was infected with COVID-19 for more than six months. The team found that the person had a string of mutations that affected the spike protein.

The immune response of an untreated HIV patient would be "too weak to clear the virus but strong enough to drive the process of evolution", said Richard Lessells, an infectious diseases physician at the University of KwaZulu-Natal.