How does SARS-CoV-2 evolve into various, increasingly contagious variants? A British study, which recently revealed that the longest infection lasted 505 days, suggests the role of immunocompromised patients, due to the persistence of the virus in their organism.
505 days is the duration of the Covid-19 infection the longest recorded so far. That’s almost a year and a half. This case remains rare because it concerns a patient immunocompromised. These patients indeed present a singular profile, because they are particularly at risk of severe form and death.
But the duration exceptional of this infection interviewed researchers from King’s College London and Guy’s and St Thomas’ NHS Foundation Trust. Who have decided to study these cases separately in order to better understand the behavior virus in these patients.
Conducted between March 2020 and December 2021, this work was unfortunately marked by the death of 4 of the 9 patients recruited. They were all either HIV positive, sick with cancer or had recently undergone an organ transplant. In the 5 patients still alive at the end of labour, the infection lasted an average of 73 days and more than a year for two of them.
Enough time to develop mutations
In these patients, the scientists observed the appearance multiple virus mutations during infection. A mutation is not quite a variantbut it allows the virus to test changes in itself on a sick person.
Objective, to be more effective for the pathogen. The mutations observed were then found in the variants that subsequently appeared during the pandemic.
This allows Dr. Luke Blagdon Snell, the main author of this work, to put forward the following theory: “these variants may have succeeded in evolve in immunocompromised individualsbecause the virus was able to persist long enough to achieve this”.
“It is therefore essential to develop new therapeutic strategies for these patients in order to eliminate the infection as quickly as possible”, underlines Dr. Gaia Nebbia, co-author. “This might prevent the emergence of new variants.”
