Integrative overview of antibodies against SARS-CoV-2 and their possible applications in COVID-19 prophylaxis and treatment

Abstract

SARS-CoV-2 is a novel β-coronavirus that caused the COVID-19 pandemic disease, which spread rapidly, infecting more than 134 million people, and killing almost 2.9 million thus far. Based on the urgent need for therapeutic and prophylactic strategies, the identification and characterization of antibodies has been accelerated, since they have been fundamental in treating other viral diseases. Here, we summarized in an integrative manner the present understanding of the immune response and physiopathology caused by SARS-CoV-2, including the activation of the humoral immune response in SARS-CoV-2 infection and therefore, the synthesis of antibodies. Furthermore, we also discussed about the antibodies that can be generated in COVID-19 convalescent sera and their associated clinical studies, including a detailed characterization of a variety of human antibodies and identification of antibodies from other sources, which have powerful neutralizing capacities. Accordingly, the development of effective treatments to mitigate COVID-19 is expected. Finally, we reviewed the challenges faced in producing potential therapeutic antibodies and nanobodies by cell factories at an industrial level while ensuring their quality, efficacy, and safety.

Understanding neutralising antibodies against SARS-CoV-2 and their implications in clinical practice

“…a Onset within 10–14 days [ 27 – 32 ]; levels remain elevated for weeks [ 30 , 33 – 38 ]; peaks at around day 25 [ 26 ]. b Rises within the first week of infection [ 30 , 31 , 33 , 39 ]; lasts 1-2 months before gradually diminishing [ 15 , 30 , 38 ]; peaks at around 20–30 days post-symptom onset [ 40 ]. c Onset within 6–8 days [ 39 ]; lasts 71 days [ 38 ]; peaks at around 20–22 days post-symptom onset [ 39 , 40 ]; high titres in severe COVID-19 cases [ 32 ] …”

“…Patients with severe COVID-19 show a significant rise in SARS-CoV-2-specific serum IgA and IgG titres after symptom onset. Response of serum IgA against S protein is detectable from 6–8 days after symptom onset [ 39 ] and peaks at around 20–22 days post symptom onset [ 39 , 40 ]. High titres of serum IgA are correlated with severe acute respiratory distress syndrome.…”

“…( n = 109) Yadav et al [ 35 ] Maharashtra, India Animal research study Serum Clinicoradiological analysis, histopathological examination, immunohistochemistry, virus isolation, ELISA IgG IgG levels were detectable from 3rd week post immunisation and were found increasing till the 35th day (7 DPI). Anti-SARS-CoV-2 IgG specific to RBD protein showed a high level of antibody response in the vaccinated group at 28th day post immunisation and 7 DPI Valdez-Cruz et al [ 39 ] Mexico City, Mexico Meta-analysis Serum Nil IgG, IgM, IgA IgM accumulation is observed within 7 days PSO. IgA titre increases principally between 8 and 21 days PSO.…”

Molecular insights into receptor binding energetics and neutralization of SARS-CoV-2 variants

“…Since the S protein has been found to be the primary antigenic epitope on SARS-CoV-2, antibodies directed against this protein can neutralize the ability of the virus to bind and fuse with the target host cell 25,26 . The traditional neutralization mechanism is to block the receptorbinding site located between RBD and ACE2.…”

Monitoring Specific IgM and IgG Production Among Severe COVID-19 Patients Using Qualitative and Quantitative Immunodiagnostic Assays: A Retrospective Cohort Study

“…Combined, these limitations of the test can lead to reduced sensitivity, which, in the context of the present pandemic, can result in a substantial number of false-negative results, thus, undermining the overall management strategy and jeopardizing the security of the healthcare system and population safety (10). Thus, it is becoming more commonly recommended to integrate the detection of specific SARS-CoV-2 antibodies within management strategy towards improving the screening, diagnosis, and follow-up of patients-both at the healthcare institutional level and in the general population (11). Accordingly, it is clinically relevant to determine previous infection or exposure to the virus and to understand the course of specific antibody production.…”