British scientists from the University of Cambridge came to the conclusion that the emergence of new mutations of coronavirus could be due to the use of blood plasma from those who had been ill in the treatment of patients with this disease. This is stated in the results of a preliminary study presented in an article on the Nature website.
"Treatment with COVID-19 antibodies appears to trigger mutations in SARS-CoV-2, which affect a person with a weakened immune system," the report said.
Scientists came to such conclusions while studying the medical history of one patient with COVID-19, who was treated with antibodies. In mid-2020, the man was hospitalized with coronavirus.
A patient with COVID-19 was treated with two courses of the antiviral drug remdesivir, and then two courses of blood plasma with antibodies from people who recovered from this disease. The patient died 102 days after hospitalization.
University of Cambridge researcher Ravindra Gupta and his colleagues analyzed viral genomes obtained from this person during his illness. The scientists found that after treatment with remdesivir, the viral populations in his blood changed little. But after each course of plasma therapy, viruses with a certain pair of mutations in the SARS-CoV-2 spike protein, the main target of the immune system, prevailed in the patient's samples.
Experiments have shown that one of the mutations weakens the activity of antibodies in the convalescent plasma, but also reduces the infectivity of the virus. Another mutation restores the infectivity of the virus.
According to the authors of the scientific work, the possibility of viral evolution means that the plasma of the recovered should be used with caution in the treatment of people with weakened immune systems.
Note that at the moment the most famous mutations of the coronavirus are British, Brazilian, South African strains. They are considered to be more infectious than the regular Covid-19 variant.
By the way, earlier WHO discovered five mutations of the coronavirus in Ukraine.