Cross-Clade Memory Immunity in Adults Following SARS-CoV-1 Infection in 2003

Area of Science:

• Immunology
• Virology
• Vaccinology

Background:

• Understanding the longevity and breadth of immune responses to coronavirus infections is critical for developing effective next-generation COVID-19 vaccines.
• Previous SARS-CoV-1 infection may influence immune responses to SARS-CoV-2.

Purpose of the Study:

• To profile SARS-CoV-2 antibodies in individuals infected with SARS-CoV-1 in 2003 (SARS03 survivors).
• To characterize the antibody response in SARS03 survivors following COVID-19 vaccination.

Main Methods:

• A prospective cohort study comparing SARS03 survivors with infection-naive controls.
• Measurement of SARS-CoV-2 antibodies (nucleocapsid, spike receptor-binding domain, neutralizing) pre-vaccination and post-COVID-19 vaccination (inactivated CoronaVac or mRNA BNT162b2).

Main Results:

• SARS03 survivors largely retained cross-reactive antibodies against SARS-CoV-2.
• Following vaccination, SARS03 survivors showed significantly higher neutralizing antibody levels compared to controls.
• A broader antibody response against SARS-CoV-2 variants, including Omicron, was observed in SARS03 survivors post-vaccination.

Conclusions:

• Prior SARS-CoV-1 infection is associated with cross-reactive and cross-neutralizing antibodies against SARS-CoV-2.
• These findings support the development of vaccines offering broad protection against sarbecoviruses, which cause significant zoonotic outbreaks.