Dynamics of the intensity of the immune response in COVID-19

Abstract

Introduction: The immune response is the main focus of research in COVID-19 due to its high clinical significance and importance for the development of vaccines and drugs. The aim of this pilot study was to determine the level and duration of circulation of Anti-SARS-CoV-2 IgG in the serum of patients who had undergone COVID-19.

Materials and methods: The content of specific IgG antibodies to SARS-CoV-2 was determined in the blood serum of 138 patients aged 22 to 90 years with a diagnosis of COVID-19/convalescent COVID-19 by enzyme immunoassay. The follow-up period was up to 150 days from the onset of the disease. The results were expressed in units of optical density (OD), positivity coefficient (PC), and titers.

Results: Noticeable increase in OP/CP of antibodies was registered by day 17 from the beginning of the disease, further, from 18 to 29 days of illness was determined progradient continued elevated levels of antibodies; "plateau" the maximum values of Anti SARS-CoV-2 IgG was detected between 30 and 75 days of the first manifestations of the disease. Further, starting from day 76 to day 150, a tendency to regression of the intensity of a specific immune response was registered. The pair regression analysis revealed the determinant "time", which has a significant impact on the intensity of the specific immune response in COVID-19.

Conclusion: The intensity of the specific immune response in a new coronavirus infection was assessed by the level of Anti SARS-CoV-2 IgG in the blood serum in the dynamics up to 150 days after the manifestation of the disease. It is shown that it is possible to predict the time of complete disappearance of protective specific Anti SARS-COV-2 IgG in the blood serum in the medium term.