This test looks for immunoglobulin G (IgG) antibodies to SARS-CoV-2, the virus that causes COVID-19. Your body produces antibodies as part of its immune response to an infection. These antibodies normally become measurable from 7 – 14 days post-infection and can indicate whether you were previously infected with the virus.
A positive result means that you have detectable levels of IgG antibodies in your blood. We do not yet know whether this means that you are immune to coronavirus or, if you are immune, how long that immunity will last.
Do not take this test if you are currently experiencing symptoms of COVID-19. Please contact 111 for guidance on what to do and to discuss testing options for a current infection.
NHS staff who are eligible can obtain a discount on this test through Blue Light Card. No other discount codes or offers can be used on this test.
This serology blood test has been developed by a global medical devices and healthcare company. It is a laboratory test using chemiluminescent microparticle immunoassay (CMIA) technology. It is CE-marked which means that it conforms with European standards for the design and manufacture of such tests. The manufacturer states that in its validation study the test detected antibodies in 100% of confirmed coronavirus cases when the sample was taken at least 14 days after symptoms first developed. The test produced a negative result in 99.6% of samples from people who did not have the infection in the same study.
The manufacturer’s validation study was conducted on venous blood samples taken from a vein in the arm. Our laboratory has conducted validation using a combination of venous and finger-prick blood samples. In the laboratory’s study, the test had a sensitivity of 98.5% which means that if 1,000 people who had previously been infected with coronavirus virus took the test, 15 of them would be told that they hadn’t had coronavirus when they had (a false negative result). It had a specificity of 99.5% which means that if 1,000 people who hadn’t had the virus took the test, 5 of them would be told they had been infected when they hadn’t (a false positive result).
We advise taking the test 21 days after the onset of symptoms. This is because our laboratory has reported a slight increase in the chances of finding detectable antibodies in samples taken between 17 and 21 days after the onset of symptoms.
This test may not accurately detect antibodies in people who have compromised immune systems because their antibody response may be slower or weakened. This may affect the reported results above. These people may have immunodeficiency diseases, infections such as HIV, or be taking medications that suppress the immune system.
The test has not yet been evaluated on people who are infected with other viruses in the coronavirus family, so it is not yet known whether these could cause a false positive result.
A negative result does not exclude a current infection particularly in those who have recently been exposed to SARS-CoV-2, or in those who currently have symptoms of COVID-19, because antibodies to the virus may not have reached detectable levels at this point.
Your anonymised data may be used to help UK agencies and other organisations understand the prevalence of coronavirus within the UK population.
This test is not for sale to, or to be used by, anyone under the age of 18.
The guidance for the turnaround time of results from this test is 3 working days from the time your sample is received at the laboratory. This excludes weekends and bank holidays. It is an estimate only and your results may take longer during busy periods.