Published online Mar 27, 2023. doi: 10.4331/wjbc.v14.i2.40
Peer-review started: August 28, 2022
First decision: November 30, 2022
Revised: December 8, 2022
Accepted: February 2, 2023
Article in press: February 2, 2023
Published online: March 27, 2023
Processing time: 205 Days and 11.2 Hours
The molecular test used in the diagnosis of coronavirus disease 2019 is very specific and sensitive, however, it is not able to detect previous exposure to the virus nor to assess immunological memory. Therefore, serological tests that have this capability are used as tools for understanding the course of the humoral immune response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).
The motivation for this study arose from the serological test developed at the Federal University of Paraná, which in the validation process showed better sensitivity than commercial tests. A more sensitive test allows specific antibodies to be detected even at low titers, and thus to effectively assess whether there is still a protective antibody response in individuals who have been infected by the virus.
The aim of this study was to identify if a pattern of SARS-CoV-2 specific immunoglobulin G (IgG) production can be determined according to the time elapsed since diagnosis of the disease/onset of symptoms. The data could indicate, for example, the interval between vaccination doses.
This study was initiated after approval by the ethics committee. The participants were tested by real-time reverse transcriptase-polymerase chain reaction, the municipal government provided us with the data. Only positive cases were included in the study. Blood collection was performed by our research team and the method used for specific IgG antibodies was the indirect enzyme-linked immunosorbent assay. Statistical analyses were performed by the statistician of the research group, one of the authors of the manuscript.
The results of the study showed that there is no time pattern for the production of specific IgG. Less than one month after infection, some participants no longer have detectable IgG in the serum, while others have the antibodies seven months after infection.
In addition to the impossibility of establishing a temporal pattern of IgG response, the data indicate that SARS-CoV-2 does not appear to induce a long-lasting humoral response.
The study perspective is to analyze the immunoglobulin M (IgM) response of the same volunteers and determine the titers of both IgG and IgM to better understand seroconversion and the robustness of the anti-SARS-CoV-2 antibody response.