COVID-19 antibody test

This test is carried out by our UKAS-accredited laboratory partners using a CE-marked antibody test. The laboratory uses your blood sample and performs the test using chemiluminescent microparticle immunoassay (CMIA) technology, which was developed by a global medical devices manufacturer and health care company. It is a CE-marked test which means the design and manufacturing of the test conforms with European standards.

In any testing accuracy is vital and we only wanted to offer a Coronavirus antibody test if we could find one, which offered precision and accuracy for our customers. Finding such a test has taken time due to the fact that this virus is so new however in working closely with our partner laboratories we have found a test, which offers a 99.6% accuracy rating, a level far higher than other tests that have been available for a few weeks.

The manufacturer states that in its validation study the test detected antibodies in 100% sensitive of confirmed coronavirus cases when the sample was taken at least 14 days after symptoms first developed (88 samples). The test produced a negative result in 99.6% of samples from people who did not have the SARS-CoV-2 infection in the same study (1070 samples). The manufacturer’s validation study was conducted on venous blood samples taken from a vein in the arm. Our UKAS-accredited laboratory in the UK 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% (132 samples) 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% (186 samples) 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).

Coronaviruses were first identified by scientists in the 1960s, and infections occur in both humans and animals. A coronavirus infection is an unpleasant but short-lived illness for the majority of people. Typical symptoms can include a sore throat, cough, fever, blocked or runny nose, sneezing, and muscle aches. Many cases of the common cold in the UK are due to coronaviruses. In most cases, the body will fight off the infection within about seven days.

A very small number of those infected can develop complications such as viral pneumonia (chest infection). Complications are most likely in people with weakened immune systems, older people, and those with long term conditions like diabetes, heart disease and chronic lung disease.

Your test results will be described as either negative, borderline or positive. A positive or borderline result does not mean that you won’t catch the virus again or carry and transmit the virus onto someone else, nor does not mean that you are immune to having another COVID-19 infection in the future.

As yet we do not know whether the presence of antibodies to SARS-CoV-2 in the blood provides lasting immunity and prevents reinfection. If it does provide immunity we do not know how long this immunity would last. In the coming weeks and months we expect to learn much more about what it means to have the presence of antibodies and if any immunity is provided the duration this may protect us.

Most antibody testing will result in a small percentage of false-positive results. In the validation study this number was very small, about 1 in 200 samples from individuals not infected with COVID-19 showed a false positive. A false positive may occur in testing for SARS-CoV-2 due to antibodies to other viruses in the coronavirus family potentially reacting with the components in the SARS-CoV-2 antibody tests. 

This antibody test was 100% sensitive in its validation study, meaning that it correctly identified antibodies to SARS-CoV-2 in all samples from people with a confirmed coronavirus infection and who were tested at least 14 days after the onset of symptoms.  Testing prior to 14 days may mean you get a negative result even if you have been infected, because your antibody level may not have reached a detectable level.

A borderline result means that IgG antibodies were not high enough to give a positive result. This means that the level of antibodies SARS-CoV-2 coronavirus found in your blood sample is too low to be defined as a clear positive result. A borderline result may mean the sample was taken too early after the infection.

If the sample was taken after 14 days we recommend you retest in 7 days, if this test was taken prior to 14 days post the onset of symptoms we recommend you retest 21 days after symptom onset. Testing after 21 days will allow for clarification of the result.

If antibodies to SARS-CoV-2 coronavirus have been found in your blood sample it is highly likely that you have been infected with COVID-19. If you are still experiencing symptoms you should continue to self-isolate as you may still be infectious. Those in your household should also self-isolate for 14 days and if possible take a test also to confirm whether they have the COVID-19 virus or take an antibody test after 21 days (if they have no symptoms) to identify whether they have antibodies to SARS-CoV-2 coronavirus.

It is important to note that as yet we do not fully understand whether having antibodies to SARS-CoV-2 coronavirus means that you have immunity from reinfection and if so how long does this immunity last for. In the coming weeks and months this will become better understood.

No. In order to get the results from this test you collect a finger prick blood sample at home in a small vial. You post this sample to our UKAS-accredited laboratory for analysis. Once the laboratory receives your blood sample, your result should be available within 3 working days.

Once you’ve ordered your test kit, we’ll send out a finger-prick blood sample collection kit in the post. You collect your sample at home and then post the sample back to our laboratory in the prepaid mailing bag. You will receive an email as soon as your results are ready, typically 3 working days from the sample being received at the laboratory. 

This test is appropriate for anyone who wants to understand whether they have had COVID-19; this means individuals who experienced mild or moderate symptoms, or those who were exposed to COVID-19 but did not experience symptoms at all.

It is important to wait 14 days from the onset of symptoms before taking this test. This is to ensure that antibody levels are detectable. If you did not experience any symptoms but were exposed to the virus this test should be taken 21 days after the last exposure.

It should be noted that the test may not accurately detect antibodies in those with a compromised immune system as their production of antibodies is weakened or slower. This may affect individuals with immunodeficiency disease such as HIV or those taking medications that suppress the immune system.

No, this test detects antibodies; these are produced some time after an individual becomes infected. In the majority of people antibodies reach detectable levels 14 days after the development of symptoms or, if you haven’t had symptoms, 21 days from possible exposure to the virus.

A polymerase chain reaction (PCR) test, looks for genetic (RNA) fragments of the virus itself. This type of testing looks for an active infection and is performed by ‘swabbing’ or collecting cells from the nose and throat. A positive PCR test means that you currently have the virus and are potentially infectious to others.

To swab correctly the device for collecting the sample must be inserted deep into the nose and back of the throat to collect cells. This can be challenging to do as a self-test and if it is performed incorrectly it means that the test result could be unreliable and there’s the possibility of missing an infection.