Next Covid-19 Strain May be More Dangerous, Lab Study Shows

(Bloomberg) -- A South African laboratory study using Covid-19 samples from an immunosuppressed individual over six months showed that the virus evolved to become more pathogenic, indicating that a new variant could cause more illness than the current predominant omicron strain.

The study, conducted by the same laboratory that was to first test the omicron strain against vaccines last year, used samples from a person infected with HIV. Over the six 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.

The study, led by Alex Sigal at the Africa Health Research Institute in the South African city of Durban, indicates that the Covid-19 pathogen could continue to mutate and a new variant may cause more severe illness and death than the relatively mild omicron strain. The study is yet to be peer reviewed and is based solely on laboratory work on samples from one individual.

Sigal and other scientists have previously 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, they 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.” <Source>

[OCS: It is currently known and given fact that viruses naturally mutate over time and that such mutations may result in increased pathogenicity. Nothing new here. For those wishing to read the actual paper, “SARS-CoV-2 evolves increased infection elicited cell death and fusion in an immunosuppressed individual. “it can be found here. While it is generally believed that viruses weaken over time to preserve their survivability in a selected host, it is not necessarily a given.]

Abstract

The milder clinical manifestations of Omicron infection relative to pre-Omicron SARSCoV- 2 raises the possibility that extensive evolution results in reduced pathogenicity. To test this hypothesis, we quantified induction of cell fusion and cell death in SARSCoV- 2 evolved from ancestral virus during long-term infection. Both cell fusion and death were reduced in Omicron BA.1 infection relative to ancestral virus. Evolved virus was isolated at different times during a 6-month infection in an immunosuppressed individual with advanced HIV disease. The virus isolated 16 days post-reported symptom onset induced fusogenicity and cell death at levels similar to BA.1. However, fusogenicity was increased in virus isolated at 6 months post-symptoms to levels intermediate between BA.1 and ancestral SARS-CoV-2. Similarly, infected cell death showed a graded increase from earlier to later isolates. These results may indicate that, at least by the cellular measures used here, evolution in long-term infection does not necessarily attenuate the virus.  <Source: SARS-CoV-2 evolves increased infection elicited cell death and fusion in an immunosuppressed individual>