Association of SARS-CoV-2 Seropositive Antibody Test With Risk of Future Infection

Area of Science:

• Immunology
• Infectious Diseases
• Epidemiology

Background:

• Understanding the impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies on infection susceptibility is crucial for public health strategies.
• Identifying populations at risk and informing vaccine deployment requires knowledge of antibody-mediated protection.

Purpose of the Study:

• To evaluate the association between SARS-CoV-2 antibody status and subsequent infection evidence.
• To analyze diagnostic nucleic acid amplification test (NAAT) results in relation to antibody test outcomes.

Main Methods:

• An observational descriptive cohort study utilized deidentified clinical laboratory, claims, electronic health records, and hospital data.
• Patients were categorized into antibody-positive and antibody-negative groups based on their initial SARS-CoV-2 antibody test.
• Primary endpoint was post-index diagnostic NAAT results, assessed in 30-day intervals.

Main Results:

• The study included over 3.2 million unique patients, with 11.6% testing positive for SARS-CoV-2 antibodies initially.
• Initially, antibody-positive patients showed a higher ratio of positive NAAT results (2.85 at 0-30 days).
• Over time, this ratio decreased significantly, suggesting protection (0.10 at >90 days).

Conclusions:

• Seropositivity for SARS-CoV-2 antibodies is associated with reduced likelihood of subsequent infection, indicating a protective effect.
• The initial higher NAAT positivity in seropositive individuals may reflect prolonged viral RNA shedding.
• The duration and waning of this antibody-induced protection remain unknown and require further investigation.