Demographic and Clinical Factors Associated With SARS-CoV-2 Anti-Nucleocapsid Antibody Response Among Previously Infected US Adults: The C4R Study - Report - MDSpire
Advertisement
Demographic and Clinical Factors Associated With SARS-CoV-2 Anti-Nucleocapsid Antibody Response Among Previously Infected US Adults: The C4R Study
Factors Influencing Anti-Nucleocapsid Antibody Responses to SARS-CoV-2 Infection
Overview
This study analyzed anti-nucleocapsid (anti-N) antibody responses in 1419 US adults with prior SARS-CoV-2 infection, revealing that antibody reactivity peaks at 4 months post-infection and declines significantly by 12 months. Key factors associated with higher anti-N responses included older age, Hispanic or American Indian/Alaskan Native ethnicity, lower socioeconomic status, former smoking, and higher anti-spike antibody levels, while vaccination and Asian race were linked to lower anti-N reactivity.
Background
COVID-19 remains a leading cause of death despite vaccination efforts, with ongoing challenges posed by SARS-CoV-2 variants. Serological studies of adaptive immune responses, particularly anti-nucleocapsid antibodies which arise only from natural infection, provide critical insights for identifying individuals at risk for adverse outcomes. Prior research on anti-N responses has been limited by small sample sizes, lack of diversity, and incomplete data on vaccination and comorbidities. Understanding anti-N antibody dynamics and correlates is essential for improving clinical classification and surveillance of SARS-CoV-2 infection.
Data Highlights
Time Since Infection
Proportion Anti-N Reactive
Up to 4 months
69%
≥12 months
44%
Key Findings
Anti-nucleocapsid antibody positivity peaked at 69% around 4 months post-infection and declined to 44% at 12 months or more.
Older age was associated with higher anti-N antibody responses.
Hispanic and American Indian/Alaskan Native participants showed higher anti-N reactivity compared to White participants; Asian participants had lower reactivity.
Lower income and education levels correlated with stronger anti-N antibody responses.
Former smokers exhibited higher anti-N antibody levels than never smokers.
COVID-19 vaccination, even after infection, was linked to reduced anti-N antibody reactivity; vaccine manufacturer and cardiometabolic comorbidities showed no association.
Clinical Implications
Anti-nucleocapsid antibody testing can aid in identifying prior natural SARS-CoV-2 infection but may underestimate infection history over time due to waning antibodies, especially beyond 12 months. Clinicians should consider demographic and vaccination status factors when interpreting anti-N serology results to avoid misclassification. These findings support the use of combined serological markers and patient history for more accurate COVID-19 surveillance and risk stratification.
Conclusion
This large, diverse US cohort study elucidates important demographic and clinical factors influencing anti-nucleocapsid antibody responses after SARS-CoV-2 infection, highlighting the dynamic nature of these antibodies and their implications for clinical and epidemiological applications.
References
C4R Study Team 2024 -- Factors Influencing Anti-Nucleocapsid Antibody Responses to SARS-CoV-2
by Ryan T Demmer, Chaoqi Wu, John S Kim, Yifei Sun, Pallavi Balte, Mary Cushman, Rebekah Boyle, Russell P Tracy, Linda M Styer, Taison D Bell, Michaela R Anderson, Norrina B Allen, Pamela J Schreiner, Russell Bowler, David A Schwartz, Joyce S Lee, Vanessa Xanthakis, Jean M Rock, Rachel Bievenue, Amber Pirzada, Margaret Doyle, Elizabeth A Regan, Barry J Make, Alka M Kanaya, Namratha R Kandula, Sally E Wenzel, Josef Coresh, Carmen R Isasi, Laura M Raffield, Mitchell S V Elkind, Virginia J Howard, Victor E Ortega, Prescott Woodruff, Shelley A Cole, Joel M Henderson, Nicholas J Mantis, Elizabeth C Oelsner
