Summary
| Direction in PACVS | ↓ Reduced — lower than in the comparison group |
|---|---|
| Category | Serologic |
| Also described as | Infection-specific marker |
| Compared against | Expected absent in vaccinated-only |
| Associated symptoms | Rules out prior SARS-CoV-2 infection |
| Test type | Blood test (serum / plasma / whole blood) |
| Source | Federico 2024 — doi:10.3390/vaccines12111281 |
| Condition atlas | PACVS Biomarker Atlas |
Trials, interventions and tests
In clinical-trial registrations this marker maps to the outcome term Maximal Handgrip Strenght (6 registered trials use a matching outcome measure).
Clinical trials using Anti-Nucleocapsid (Anti-N) antibodies as an outcome
- NCT06928272: Long Covid (LC)-REVITALIZE - A Long Covid Repurposed Drug Study (Recruiting)
Outcome measure: Quantitative measurement of biomarkers specific to relevant inflammatory pathways and to Long Covid identified previously (The LC-Optimize Study) - NCT06766825: Study to Evaluate the Efficacy and Safety of Plitidepsin in Adults With Post-COVID-19 Condition (PCC) (Recruiting)
Outcome measure: To compare immune response markers: Antinuclear antibodies (ANAs) in patients with persistent COVID among the three treatment arms. - NCT06437223: Study of Xiflam™ Treatment in Patients Post COVID-19 Infection Suffering From What is Known as Long COVID (LC) (Completed)
Outcome measure: Secondary Endpoint - NCT04695704: Efficacy of Montelukast in Mild-moderate Respiratory Symptoms in Patients With Long-COVID-19: (Terminated)
Outcome measure: Factors of inflamatory and prothrombotic processes: D-Dimer, N-terminal prohormone of brain natriuretic peptide (NT Pro-BNP), C-reactive protenin and Antinuclear antibodies (ANA) - NCT05793736: Prevention of Long Covid Syndrome (Completed)
Outcome measure: Change from Baseline to 5 weeks and to 9 weeks in Stroop Test (Caffarra et al.; 2002) score - NCT05629884: Efficacy of a Physical and Respiratory Rehabilitation Program for Patients With Persistent COVID-19 (SARS-CoV-2). (Unknown)
Outcome measure: Maximal Handgrip Strenght
Commercial test availability
SARS-CoV-2 Nucleocapsid Antibody — commercial laboratory test.
Links are for reference only; availability, specimen requirements and coverage vary by location.
Related Serologic markers in PACVS
Full list: PACVS Biomarker Atlas.
Frequently asked questions
Is Anti-Nucleocapsid (Anti-N) antibodies high or low in PACVS?
Reduced. Studies summarised in the OSMF atlas report lower Anti-Nucleocapsid (Anti-N) antibodies in PACVS than in Expected absent in vaccinated-only. Source: Federico 2024.
What symptoms is Anti-Nucleocapsid (Anti-N) antibodies associated with in PACVS?
The cited literature associates this marker with Rules out prior SARS-CoV-2 infection. These are population-level associations and do not mean the marker causes the symptoms.
Which test measures Anti-Nucleocapsid (Anti-N) antibodies?
It is measured as a blood test (serum / plasma / whole blood). Commercial laboratories such as Quest Diagnostics, LabCorp list an orderable assay.
Is one abnormal Anti-Nucleocapsid (Anti-N) antibodies result diagnostic of PACVS?
No. No single biomarker is diagnostic of PACVS. Anti-Nucleocapsid (Anti-N) antibodies findings come from group comparisons, overlap considerably between patients and controls, and vary with study design, timing and comparison group. A result should be interpreted by a clinician alongside symptoms, history and other tests.
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Last reviewed: 2026-06-30 · Page generated from pacvs.json · Browse: PACVS atlas · Biomarker Index · All marker pages
Disclaimer: This page is an educational synthesis of published, peer-reviewed research and is not medical advice. Biomarker findings vary across studies with case definitions, comparison groups, timing and assay methods. Direction of change reflects the predominant finding in the cited source and does not establish a diagnostic threshold. Discuss any test result with a qualified clinician.