Fresh plasma from Covid-19 recovery.
Photographer: Omar Marques / Getty Images
Photographer: Omar Marques / Getty Images
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British doctors who treated a cancer survivor of Covid-19 for 102 days documented how the virus mutated after the man was treated with a recovery plasma.
The case study suggests that the use of blood plasma donated by Covid-19 survivors may have put enough pressure on the virus to allow it to develop. The result: Less susceptibility to antibodies to immune systems that normally fight infection, according to the report published Friday in the journal Nature.
Although the recovery problem does not harm the patient, it does not provide a clear benefit, senior author said Ravindra Gupta, a professor of clinical microbiology at the Cambridge Institute of Therapeutic Immunology and Infectious Disease. It should be used with caution in people with chronic immune conditions, he said, preferably in clinical trials or carefully controlled settings.
The report also suggests that numerous mutations may occur among patients with immune systems and chronic infections.
“If the virus has the chance to sit in one person for a long time and repeat it for weeks and months, it learns how to fight the immune system,” Gupta said. It’s all about ‘pressing the virus’.
The patient did not develop the exact variant that has now become the dominant form of the virus circulating in the UK, the report said, but it had certain elements in common. “It just illustrates that someone like him is probably patient,” Gupta said.
Slow mutations
In general, Covid-19 mutates relatively slowly. This is because it is a fast moving virus that gives it little time to develop. In this case, however, the patient and his doctors battled the virus for 102 days from the time he was diagnosed until he died, Gupta said.
The patient was diagnosed with Covid-19 at a local hospital in the spring of 2020 when the first wave of the virus reached crisis levels in the UK. He was then taken to Cambridge University hospitals for more intensive care.
The team tested him twice a week to see if the treatments he was receiving, including Gilead Sciences Inc. ‘s brake desivir reduced its virus load. They were not.
Genetic profiling
At the same time, the samples are sent for genetic profiling. This led to a screenshot of the virus mutating over time, which allowed the researchers to examine where, how and when the pathogen changes as the months progress.
According to the researchers, there were few changes in the virus after receiving two courses of inhibitor in the first two months. However, after recovery plasma was administered, there was a large, dynamic virus population shift, including the major protein that the virus uses to retain and infect healthy cells.
The variants then provided evidence of reduced susceptibility to neutralizing antibodies that normally control the virus.
Large study
The case study comes almost a month after a large, national study in the UK investigating plasma recovery as a therapy was terminated after the treatment proposed by US President Donald Trump was found to not work.
The University of Oxford research was part of a clinical trial called Recovery examining different Covid-19 treatments. The other arms of the study continue.
The results come after more than 100,000 Americans were treated with recovery plasma after U.S. regulators approved it on an emergency basis.