Scientists Skolteha published a study in which a record-long case of a coronavirus infection that lasted 318 days is disclosed in detail. The preprint of the article is available on the website Research Square.
The patient, denoted as C, was a sick non-Hodgkin B-cell lymphoma and received a positive test for Coronavirus in April 2020, and the first negative test was obtained for almost a year – in March 2021. During this time, a woman suffered several times from serious symptoms, including the heat and inflammation of the lungs.
Scientists followed the evolution of SARS-COV-2 in the patient’s body using full-bent sequencing and phylogenetic analysis, which confirmed that all this time the woman suffered from the same infection. During the year, the virus has undergone 40 mutations, which is much faster than this happens in the population. SARS-COV-2 has adapted to the body of one person, improving its ability to survive and multiply multiply. Some mutations affected the S-protein and were similar to those observed in other patients.
It was previously that mutations in S-protein are fixed in response to the effect of neutralizing antibodies, but the patient with did not have in-lymphocytes, and it almost absent IgG antibodies. In addition, many mutations fell on proteins that are not on the surface of the viral shell. This is due to the fact that the patient still acted T-cell immunity, which is capable of recognizing any proteins encoded in the genome of the virus. Thus, SARS-COV-2 has acquired protection that allows the virus to withstand only the part of the immunity that has been preserved in the patient.
Scientists confirmed that the mutations accumulated by the virus allowed him to avoid the presentation of antigens by alleles of the main histocompatibility complex (GKG) of the patient, making the T-cell immune response ineffective. GKG presents alien molecules T-cells for recognition and subsequent pathogen destruction. Probably, new strains that are characterized by increased resistance to antibodies could also arise and quickly accumulate mutations in the body of people with a weakened immune system.