Nature: Chronic SARS-CoV-2 infections can trigger mutations

FEBRUARY 7, 2021 /--- -- A team led by Cambridge researchers recently published an article in the journal Nature on how they observed the SARS-CoV-2 mutation in immunodeficiated patients receiving restorative plasma therapy.
, they see a key mutation in the new variant that led to another large-scale "blockade" of the UK.
team used laboratory-created variants of the virus to find specific changes in its genetic code that made the virus twice as infectious on cells as normal strains.
(Photo Source: Www.pixabay.com) The tingling protein structure on the surface of the virus gives it a characteristic coronary shape, which the virus uses to attach to the ACE2 complex on the surface of the host cell, allowing it to enter the cell, hijack its machine, and allow it to replicate and spread in the human body.
most vaccines currently in use or being trial are targeted at prickly proteins, and there are concerns that mutations could affect the effectiveness of these vaccines.
British researchers in the COVID-19 Genomics UK (COG-UK) alliance led by Cambridge, UK, have identified a particular variant of the virus, including important changes that could make it more contagious: the absence of amino acids in some hedgehog proteins, one of the key changes in the variant.
that although the absence of H69/V70 has been detected many times, until now, scientists have not seen them appear in patients.
, in a study published today in the journal Nature, researchers at the University of Cambridge documented how these mutations appeared in PATIENT-19 patients.
patient was a man in his 70s who had previously been diagnosed with marginal B-cell lymphoma and had recently undergone chemotherapy, which meant his immune system was severely compromised.
hospitalization, a variety of treatments were available to patients, including the antiviral drug reddoxev and recovery plasma, which contains antibodies extracted from the blood of patients who successfully removed the virus from the system.
although his condition initially stabilized, it began to deteriorate.
he was admitted to the intensive care unit for further treatment and eventually died.
the patient was hospitalized, a total of 23 virus samples were isolated, most of them from his nose and throat, in which the researchers observed a genetic mutation in the virus.
Between the 66th and 82nd days after the first two convalescent serums were restored, the team observed significant changes in the viral population, with the absence of variants of H69/V70 and the tinge protein mutation called D796H as an advantage.
although the mutation initially appeared to have disappeared, it re-emerged after a third treatment of remxive and recovery plasma.
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" winning virus (with the D796H mutation and the absence of H69/V70) initially gained the upper hand in rehabilitation plasma therapy and was replaced by other strains, but reappeared after resuming treatment.
", under strict control, the researchers created and separately tested viruses with the missing H69/V70 and D796H mutations.
mutations make the virus less sensitive to the neutral effects of recovery plasma, although it appears that individual D796H mutations are the cause of reduced antibody sensitivity in the plasma.
in the absence of plasma, only the D796H mutation causes the loss of infection, a typical mutation that the virus obtains to escape immune stress.
researchers found that the absence of H69/V70 itself made the virus twice as infectious as previous variants.
that the missing role is to compensate for infectious loss caused by the D796H mutation. Professor Gupta added:
In view of the fact that both vaccines and treatments target the prickly proteins that mutate in our patients, our study raises the worrying possibility that virus mutations could beat our vaccine.
" (Bioon.com) Source: Study highlights risk of new SARS-CoV-2 mutationsemerging when chronic infect source: Kemp, SA et al. SARS-CoV-2 evolution during treatment of chronic infection. Nature; 5 Feb; DOI: 10.1038/s41586-021-03291-y