Cross-Neutralizing Breadth and Longevity Against SARS-CoV-2 Variants After Infections

Area of Science:

• Immunology
• Virology
• Public Health

Background:

• The COVID-19 pandemic is driven by SARS-CoV-2, with variants of concern (VOCs) posing significant public health challenges.
• Understanding the cross-neutralizing activity and duration of protective immunity from convalescent sera against VOCs is crucial for disease control.

Purpose of the Study:

• To investigate the cross-neutralizing activity of COVID-19 convalescent sera against SARS-CoV-2 VOCs.
• To determine the longevity of neutralizing antibody responses in patients post-infection.

Main Methods:

• Sera were collected from 42 patients at 1-3, 3-6, and 6-8 months post-SARS-CoV-2 onset.
• A virus neutralization assay was performed using authentic SARS-CoV-2 strains, including D614G and VOCs (B.1.1.7, P.1, B.1.351).

Main Results:

• Neutralizing activity was sustained for 3-8 months in sera from 28 patients.
• Antibody titers against the D614G strain decreased significantly by 6-8 months post-onset.
• Importantly, neutralizing antibody titers against the three VOCs showed no significant decrease across the 1-8 month post-onset period.

Conclusions:

• Neutralizing antibodies targeting common epitopes across variants may persist long-term.
• Rapidly produced, variant-specific antibodies may decline more quickly, highlighting the importance of broadly neutralizing responses.