In addition to some drug therapies working to prevent severe courses of Covid-19, they also apparently carry the risk that new, more resistant variants will form as they are taken. German scientists have now proven that: In “Cell Reports Medicine” they published the results of a study in corona patients treated with remdesivir.
The research team of the University Medical Center Hamburg-Eppendorf (UKE) and the Leibniz Institute of Virology (LIV) investigated whether patients with long-term infections contribute to the development of new SARS-CoV-2 variants. The experts, led by Nicole Fischer (UKE/Virology) and Adam Grundhoff (LIV/Virus Genomics), examined whether Covid-19 patients with infections that could not be controlled for a long time generally have increased virus evolution or that certain forms of treatment stimulate the emergence of new ones and promote mutations.
“Evolutionary Bottleneck”
The focus was mainly on antiviral therapies, for example with remdesivir or restorative plasma. “Our work shows that it is not the long duration of the infection itself that leads to the formation of new variants, but that there is a need for an ‘evolutionary bottleneck’, such as can arise with antiviral treatment,” said Nicole Fischer.
The study examined genomic diversity in longitudinal samples from 14 patients with long-term viral exposure (30 to 146 days) during severe Covid-19 illness. This also included immunocompromised and immunocompetent patients with or without antiviral treatment to assess the occurrence of mutations with and without selection pressure in the study.
Significant increase in new mutations
The result: Patients with long-term SARS-CoV-2 infection and antiviral remdesivir treatment showed a significant increase in viral diversity with newly emerging mutations. In contrast, the emergence of new variants was observed only sporadically in patients receiving anti-inflammatory treatment alone.
“Overall, the virus was surprisingly stable in most of the people studied. However, in a patient treated with remdesivir, we found that a large number of mutations developed immediately after the start of treatment, including at least one mutation that most likely causes increased resistance to remdesivir,” explains Grundhoff.
Paxlovid outperformed
In recent months, there have been isolated scientific studies that have pointed to the possibility of resistance to the Covid-19 therapies developing. Monoclonal antibodies have repeatedly lost their effectiveness due to new virus variants, because they specifically target one or a few variants.
Until now this has been less dramatic with substances such as Paxlovid, which is widely used in Austria – this has an effectiveness of about 90 percent. On the other hand, no new virus variants have developed noticeable resistance during treatment.
Source: Krone
I’m Wayne Wickman, a professional journalist and author for Today Times Live. My specialty is covering global news and current events, offering readers a unique perspective on the world’s most pressing issues. I’m passionate about storytelling and helping people stay informed on the goings-on of our planet.
