Potent and Persistent Antibody Response in COVID-19 Recovered Patients

Area of Science:

• Immunology
• Virology
• Infectious Diseases

Background:

• The COVID-19 pandemic, caused by SARS-CoV-2, has led to significant global health challenges.
• Understanding the duration and nature of the antibody response is crucial for assessing long-term immunity.

Purpose of the Study:

• To investigate the persistence and characteristics of SARS-CoV-2 specific antibody responses in recovered patients.
• To evaluate the neutralization potency of these antibodies over time.

Main Methods:

• Enzyme-Linked Immunosorbent Assay (ELISA) was employed using purified SARS-CoV-2 spike (S) and nucleocapsid (N) proteins.
• A surrogate viral inhibition assay utilizing a SARS-CoV-2 S protein pseudovirus system was established.
• Analysis of 484 serum samples from recovered patients collected between 154 and 193 days post-recovery.

Main Results:

• A high prevalence of SARS-CoV-2 specific antibodies was observed, with 92% positive for spike glycoprotein IgG (s-IgG) and 63% for spike glycoprotein IgM (s-IgM).
• Moderate to potent virus neutralization activity was detected in 62% of the samples.
• A significant positive correlation was found between s-IgG response and neutralization activity.

Conclusions:

• Recovered patients exhibit a durable antibody response against SARS-CoV-2, extending beyond 150 days.
• The presence of s-IgG correlates with functional virus neutralization, suggesting a protective immune memory.
• These findings support the potential for long-lasting immunity in individuals who have recovered from mild to moderate SARS-CoV-2 infection.