What Is HIV p24 Antigen?
What it is
HIV p24 capsid antigen
Why it matters
Appears before antibodies, narrowing the HIV window period.
Specimen
WB/S/P
Interpretation
Positive = early HIV antigen
Limitations
Reactive requires confirmation
Related test: HIV p24 Antigen Rapid Test — specimen: WB / S / P
Frequently Asked Questions
Why test HIV p24 antigen? It appears before antibodies, narrowing the HIV window period.
Related knowledge
References
- WHO. Consolidated guidelines on HIV testing services.
Last reviewed: 2026-09-12