HIV I & II Antibody & p24 Antigen Test
Private fourth-generation HIV testing in London for £60.99, detecting HIV-1/2 antibodies and p24 antigen with results in around 1 day.
Turnaround time
1 business day
Biomarkers count
1
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Overview of the HIV I & II Antibody & p24 Antigen Test
The HIV I & II Antibody & p24 Antigen Test is a fourth-generation laboratory HIV screening test that detects antibodies to HIV-1 and HIV-2 together with HIV p24 antigen.
The test contains 1 combined biomarker: HIV 1 & 2/p24Ag.
After HIV infection occurs, different markers become detectable at different stages.
HIV RNA becomes detectable first, followed by viral p24 antigen and then the person's antibody response.
Fourth-generation testing combines antibody and antigen detection, allowing infection to be identified earlier than with antibody-only tests.
This is the standard type of laboratory screening test widely used for HIV diagnosis in clinical practice.
The timing of testing following exposure remains important.
Current UK HIV testing guidance applies a 45-day window period to fourth-generation laboratory serology for reliable exclusion of HIV following an exposure, although many infections become detectable earlier.
If the test is performed before the full window period has passed, a negative result may require repeat testing.
PrEP, PEP or very early antiretroviral treatment can complicate the timing and interpretation of HIV testing and should always be disclosed.
A reactive fourth-generation result does not by itself establish a final HIV diagnosis.
Reactive screening samples require confirmatory testing through the appropriate laboratory pathway.
HIV testing is confidential, and early diagnosis is important because modern antiretroviral treatment is highly effective.
What Does the HIV I & II Antibody & p24 Antigen Test Check?
The test combines HIV-1 and HIV-2 antibody screening with detection of p24 antigen, providing earlier detection than antibody-only serology. This test measures 1 combined biomarker.
HIV 1 & 2/p24Ag
Detects antibodies to HIV-1 and HIV-2 together with p24 antigen in a fourth-generation laboratory screening assay.
Who May Benefit From the HIV I & II Antibody & p24 Antigen Test?
Fourth-generation HIV testing may be appropriate after potential exposure, as part of routine sexual-health screening or where HIV testing is clinically recommended.
People following condomless sexual contact - HIV testing can provide reassurance or identify infection following a relevant exposure.
People with a new sexual partner - Routine screening can form part of sexual-health care.
People with multiple sexual partners - Regular testing may be appropriate depending on individual exposure risk.
People whose partner has HIV or an unknown HIV status in a relevant risk situation - Testing and prevention advice may be appropriate.
People following blood or needle exposure - HIV testing may form part of a post-exposure pathway.
People undertaking routine confidential STI screening - HIV can remain asymptomatic for a prolonged period.
People with symptoms compatible with acute HIV following recent exposure - A fourth-generation test is appropriate, although viral-load testing may also be required in suspected primary infection.
People completing follow-up after HIV PEP - Testing timing should follow the clinical schedule provided by the sexual-health service.
People taking PrEP who require routine HIV monitoring - HIV screening forms an important part of PrEP care.
How to Prepare
Do not delay urgent PEP assessment in order to wait for this test.
A negative result obtained before the appropriate window period has passed may need repeat testing.
Symptoms and Reasons to Consider the HIV I & II Antibody & p24 Antigen Test
HIV infection can produce no symptoms, and acute HIV symptoms are non-specific, making laboratory testing the only reliable way to establish HIV status.
No symptoms following a potential exposure - Absence of symptoms does not exclude HIV.
Fever following a recent relevant exposure - Acute HIV can cause a non-specific febrile illness.
Sore throat with other acute viral symptoms - Primary HIV can resemble many ordinary viral infections.
Swollen lymph nodes - Generalised lymph-node enlargement can occur during acute HIV but has many other causes.
A widespread unexplained rash after a relevant exposure - Rash can occur in primary HIV infection.
Night sweats or marked fatigue with appropriate exposure risk - These symptoms are non-specific but may prompt testing.
A partner diagnosed with HIV - Clinical advice can establish the appropriate testing and prevention pathway.
A recent high-risk exposure - Testing should be combined with timely advice about PEP where relevant.
Symptoms cannot confirm or exclude HIV infection.
If a potentially significant HIV exposure occurred within the previous 72 hours, seek urgent sexual-health or emergency advice about post-exposure prophylaxis, because PEP is time-sensitive and should not wait for a routine test result.
How to Book Your HIV I & II Antibody & p24 Antigen Test
The fourth-generation HIV test can be booked privately and confidentially through London Blood Tests.
Choose the HIV I & II Antibody & p24 Antigen Test
Select the individual fourth-generation HIV screening test online.
Select your sample collection option
Choose an in-clinic venous blood draw or professional home or hotel phlebotomy where appropriate.
Attend your appointment
A trained healthcare professional collects the required blood sample confidentially.
Laboratory analysis
Your sample is analysed for HIV-1/2 antibodies and HIV p24 antigen using a fourth-generation screening assay.
Receive your results securely
Your authorised HIV result is delivered securely, with appropriate confirmatory follow-up advised for any reactive screen.
When Will I Receive My Results?
The current expected turnaround for the HIV I & II Antibody & p24 Antigen Test is approximately 1 business day after laboratory receipt.
Fourth-generation HIV screening is routinely performed in specialist virology laboratories and is generally available quickly.
The laboratory completes assay processing, quality-control checks and result authorisation before release.
Turnaround begins once the blood sample reaches the laboratory rather than necessarily from the exact time of collection.
If the initial screening test is reactive, the sample requires confirmatory testing before a diagnosis can be established.
This can extend the final reporting time because a reactive screening result is not considered definitive on its own.
Understanding Your Results
A negative result means neither the relevant HIV antibodies nor p24 antigen were detected by the assay.
If the test was performed 45 days or more after the relevant exposure, a negative fourth-generation laboratory test is considered reliably exclusionary under UK adult HIV testing guidance in most routine circumstances.
Earlier negative results may still be reassuring but can require repeat testing after the window period.
A reactive result means HIV antibodies and/or p24 antigen have been detected by the screening assay.
This result requires confirmatory laboratory testing before HIV infection is diagnosed.
PrEP, PEP or very early antiretroviral therapy can occasionally complicate standard testing patterns and should be considered.
Anyone receiving a confirmed positive diagnosis should be linked promptly with specialist HIV care, where highly effective antiretroviral treatment is available.
Why Book With London Blood Tests?
London Blood Tests provides confidential private fourth-generation HIV screening with rapid laboratory turnaround.
Fourth-generation HIV testing - Detects HIV-1/2 antibodies together with p24 antigen.
Earlier detection than antibody-only testing - Inclusion of p24 antigen shortens the diagnostic window.
Recognised UK laboratory approach - Fourth-generation testing is standard first-line HIV screening.
Confidential private testing - Results are delivered discreetly and securely.
Suitable for asymptomatic screening - HIV can occur without symptoms.
Rapid results - Current turnaround is approximately 1 business day.
Professional venous blood collection - Clinic and suitable mobile phlebotomy are available.
Clear pricing - The HIV I & II Antibody & p24 Antigen Test costs £60.99.
Private HIV I & II Antibody & p24 Antigen Test in London
London Blood Tests provides private fourth-generation HIV testing in London for people seeking confidential HIV screening.
The test costs £60.99 and measures 1 combined biomarker: HIV 1 & 2/p24Ag.
Results are expected approximately 1 business day after laboratory receipt.
Current UK guidance uses a 45-day window period for reliable exclusion of HIV with fourth-generation laboratory testing. Earlier testing can still be useful, but repeat testing may be required.