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HIV I & II Antibody & p24 Antigen Test
60.99
This fourth-generation HIV test detects both HIV antibodies and the p24 antigen. It allows earlier and highly accurate detection of HIV infection.
Turnaround time
1 day
Biomarkers count
1
Same-Day Appointments
UKAS Accredited Labs
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Under 18? Patients under 18 can only be seen at GB Medlabs and Clinilabs, Monday to Friday only.
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Details about HIV I & II Antibody & p24 Antigen Test
What is the HIV I & II Antibody & p24 Antigen test?
The HIV I & II Antibody & p24 Antigen test is a fourth-generation HIV screening test that detects HIV-1 and HIV-2 antibodies as well as the p24 antigen, a viral protein that appears early after infection.
Unlike older antibody-only tests, this test can identify HIV infection earlier, because p24 antigen becomes detectable before antibodies are fully formed. This significantly shortens the diagnostic window period.
It is the standard first-line HIV screening test used in clinical practice, sexual health clinics, and hospitals.
Why do I need an HIV I & II Antibody & p24 Antigen test?
Early and accurate HIV detection is essential for timely treatment, reducing transmission risk, and protecting long-term health.
You may need this test if you:
- Had unprotected sexual contact
- Have a new or multiple sexual partners
- Were exposed to blood or body fluids
- Want routine sexual health screening
- Are testing after a recent risk exposure
- Need confirmation before or after PCR testing
- Require reassurance with a highly reliable test
Situations where this test is commonly used include:
- Routine HIV screening
- Post-exposure testing (after the window period)
- Antenatal screening
- Pre-procedure or occupational health testing
Benefits of the HIV I & II Antibody & p24 Antigen test
- Early HIV detection
Identifies infection sooner than antibody-only tests. - Detects both HIV-1 and HIV-2
Comprehensive screening coverage. - Shorter window period
Increased accuracy from around 18–45 days post-exposure. - Clinically recommended first-line test
Used across NHS and private healthcare. - Highly sensitive and specific
Minimises false negatives and positives. - Single blood test
Simple and efficient screening. - Supports early treatment initiation
Improves long-term health outcomes. - Essential for sexual health screening
Reliable reassurance when results are negative.
Step by step – how the test works
You can access HIV I & II Antibody & p24 testing UK-wide through two options:
- Clinic appointment
Attend your nearest UK clinic where a healthcare professional will take your blood sample. - At-home or hotel visit (£60 extra)
A qualified phlebotomist comes to your home or hotel for discreet blood collection.
Your sample is analysed in an accredited UK laboratory, and results are delivered securely.
Your results explained
Negative result
No HIV-1 or HIV-2 antibodies and no p24 antigen detected. HIV infection is unlikely at the time of testing.
Typical UK interpretation:
- HIV antibodies: Negative
- p24 antigen: Negative
Positive or reactive result
HIV antibodies and/or p24 antigen detected. Further confirmatory testing is required.
Typical UK interpretation:
- HIV screening test: Reactive
Indeterminate / confirmatory testing required
Occasionally, additional tests such as PCR are needed to confirm the result.
All reactive results must be confirmed before diagnosis.
How It Works
Simple steps to get your results
1
Book Online
Choose your test online and book in seconds. Select your preferred clinic location or home visit option.
2
Visit or Test at Home
Attend one of our UK or London clinics, arrange a home nurse visit, or use a finger-prick kit where available.
3
Get Your Results
Your sample is analysed by accredited UK laboratories, with secure results delivered directly to you.
Take control of your health with London Blood Tests
WhatsApp UsHow to Prepare for Your Test
Follow these guidelines for accurate results
Sample Timing
Where possible, attend your blood test between 7am and 12pm. Please wait until any short-term illness or infection has fully resolved before testing. Avoid intense exercise for 24–48 hours beforehand, as this can affect certain markers.
Fasting & Hydration
Fasting is not always required, but some tests may recommend it. If fasting is advised, avoid food for 8–12 hours before your appointment and drink water only. Stay well hydrated, as this helps with sample collection and accuracy.
Medications & Supplements
Continue prescribed medications unless advised otherwise by your clinician. Avoid vitamin, mineral, or biotin supplements for at least 24–48 hours before your test, as these can interfere with results. If you are unsure about any medication or supplement, please let us know before your appointment.
Hormones & Menstrual Cycle
For hormone-related tests, timing within your menstrual cycle may be important. If relevant, follow any specific guidance provided on your test page.
If you have any questions or special circumstances, our team is happy to advise before your appointment.
Frequently Asked Questions
Usually from 18–45 days after exposure.
Yes. It detects infection earlier.
No. PCR is used earlier or for confirmation in some cases.
No fasting is required.
Yes. It screens for both HIV-1 and HIV-2.
Yes. It is the standard HIV screening test.
Rarely. Always disclose current medications.
Yes. Results are handled securely and discreetly.
Yes. Home or hotel phlebotomy is available UK-wide for £60 extra.
Yes. Immediate clinical follow-up is essential.
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