Frequently Asked QuestionsFrequently Asked Questions for Antibody Testing
When should you get a coronavirus antibody test?
The best time to perform antibody test is usually after 14 or 21 days after your first symptom or presume exposure. Our serology test has up to 99% sensitivity and specificity to SARS-CoV-2 and fall within the requirements of Department of Health and Social Care (DHSC) criteria for Antibody Testing. If you have symptoms, you should have the RT-PCR test to identify whether you currently have the active virus as serology test usually don’t pick early or active infection.
How does the COVID-19 antibody test work?
Covid-19 antibody testing is done by having a blood sample taken in clinic by a Healthcare Professional or can be done at home via a finger-prick sample. It is then sent to our laboratory for analysis. Unlike instant test or rapid tests, laboratory-based tests guarantee results are analysed in a controlled, sterile environment with minimum risk of contamination.
How reliable is the coronavirus antibody test?
We used validated assays from UK leading diagnostic brands including Bio-Rad and EUROIMMUN who have ELISA kits validated by Public Health England’s Technology Validation Group.
N-protein antibody test and Spike antibody test
Our portfolio of serological test includes N-protein SARS-CoV-2 Total Antibody (Igm/IgA/IgG) test or individual assay antibody tests (IgM, IgA or IgG) for differential prediction of window of infection or previous infection with SARS-CoV-2 virus. Our home self-taken antibody tests samples are primarily for detecting antibodies against previous infection to SARS-CoV-2 virus.
The quantitative spike (S) protein antibody test from EUROIMMUN (QuantiVac IgG ELISA) measures immune response antibodies against the Spike protein of SARS-CoV-2. Many vaccines are based on the spike protein thereby causing an antibody response against the spike protein. By testing spike protein levels before vaccination and then at intervals afterwards, we may be able to understand how individuals respond to vaccines. This in-clinic test looks for immune response to vaccination. The presence of IgG antibodies helps to identify if you have responded to previous vaccination.
What does a positive result mean?
A positive result indicates that you have antibodies to SARS-CoV-2 in your blood. This means it is highly likely that you have been infected with the virus in the past.
If I get a positive result does that mean I’m contagious?
This test is for antibodies for COVID-19. These are formed in response to infection with Covid-19 and are best detected over 20 days after infection began. This test therefore does not tell you if you are currently contagious.
Does a positive antibody test mean I am immune to Covid-19?
It is not yet known if the presence of antibodies to SARS-CoV-2, the virus that causes Covid-19, means an individual has lasting immunity. This will become clearer over the next few months as we learn more about the virus. As such you should continue to follow the current government guidelines around social distancing and self-isolation, regardless of your result.
What does a negative result mean?
A negative result indicates that you do not have antibodies to SARS-COV-2 in your blood. This means it is unlikely that you have had Covid-19. However, it is important to note that a negative antibody result could mean that you have taken the test too soon after developing symptoms. It can take at least 14 days for the body to produce antibodies at detectable levels. Please note that in some cases, people who have previously had the virus have not tested positive on the antibody test.
Can you tell me what my antibody levels are?
This antibody test will provide a positive (antibodies detected) or negative (antibodies not detected) result only. It is important to note that we do not yet know whether antibodies offer definitive protection against COVID-19 re-infection, and if so, at what level, or how long for.
Will a coronavirus antibody test tell me if I have a current infection?
No. The antibody test will not detect a current infection. Antibodies are produced some time after an individual becomes infected. If you have symptoms, you can book RT-PCR test while following local guidelines on self-isolation.
Is there any difference between antibodies produced as result of vaccination?
If an individual has been infected with SARS-CoV-2, they may have detectable antibodies to both the nucleocapsid (N) and the spike protein receptor-binding domain (RBD).
If an individual has been vaccinated against SARS-CoV-2, with no history of natural infection, the antibodies they develop are to the spike protein receptor-binding domain (RBD). Determining the levels of these antibodies could play a role in establishing vaccine efficacy and vaccine-induced immune response.