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Due to the new strains of COVID-19 and the lack of effective vaccines against them, investigations in the use of monoclonal antibodies in preventing the severe infection in comorbid patients with CKD 5D are highly relevant. The aim of our study was to evaluate the efficacy of monoclonal antibodies (tixagevimab AZD8895 and cilgavimab AZD1061) against different strains of SARS-Cov-2 for pre-exposure prophylaxis of severe COVID-19 infection in patients undergoing hemodialysis.
26 patients on permanent hemodialysis, mean age 57.4±19.6 years, (16 m and 10 f) were included in this open prospective study. All patients had additional risk factors for severe COVID-19 infection (16 cardiovascular disease, 6 diabetes mellitus, 4 obesity).All participants had been vaccinated with Gam-Covid-Vac vaccine (Sputnik V) 1 year ± 4 months previously. 12 patients had a new coronavirus infection, more than one year ago. Control group 144 patients receiving permanent hemodialysis mean age 56.2±18.3 years, (76 m and 68 f). For pre-exposure prophylaxis, the study group used monoclonal antibodies tixagevimab AZD8895 and cilgavimab AZD1061, from Astra Zeneca (“Evusheld”). In our study, the drug was administered 300 mg of each component intramuscularly after the hemodialysis session. The study was conducted from February 2023 to August 2023. The total titer of RBD-specific IgG antibodies was estimated using the SARS-CoV-2-RBD-ELISA kit (Gamaleya NRCEM, Russia). Serum dilutions ranging from 1:50 to 1: 1638400 were prepared preliminary. Serum samples negative for the presence of IgG specific to SARS-CoV-2 virus were used as a control. The level of virus neutralizing antibodies (VNA) was determined by neutralization reaction in a "constant dose of virus - multiple dilutions of serum" design. Twofold dilutions of control and test sera were prepared in DMEM culture with 2% inactivated fetal bovine serum, then mixed with 100 TCID50 of SARS-CoV-2 virus, incubated for 1 hour at 37ºC and added to Vero E6 cells. The cells incubated at 37ºC in a CO2-enriched atmosphere (5% vol/vol). After 96 hours, the evaluation of the development of cytopathic effect of the virus on the cell culture was performed visually by assessing the disruption of the cell monolayer. SPSS-20 program with calculation of nonparametric Wilcoxon criterion was used to analyze the results, with the degree of reliability of the criterion p<0.05 (95%).
The Evusheld showed no specific antiviral activity against the new COVID-19 strains, but was effective in preventing severe cases of infection, possibly due to a significant increase in titers of IgG specific to the receptor-binding domain of the SARS-CoV-2 virus.