Covid-19 Vaccine Immunity Test

Find out if you have made antibodies following a COVID-19 Vaccination.

Covid-19 Vaccine Immunity Test



About this test

This test looks for COVID-19 spike protein antibodies in a blood sample. All currently available vaccines use the spike protein to produce an immune response. A positive antibody result indicates that you have produced antibodies in response to the vaccine.

Please note: these tests are available for people aged over 18 only. In a small number of cases, it may not always be possible to provide a result, please see our terms and conditions for details.

Understanding your vaccine immunity test result

The difference in antibody levels between individuals is not currently well understood. The range of positive values that can be measured by our vaccine immunity test is from 0.8 U/mL to 2500 U/mL (U stands for units). We see values across this range and above.  The presence of any detectable antibody i.e. a positive test, is associated with protection from a severe form of COVID-19. Beyond this, there is currently not enough evidence to relate antibody levels to a level of immune response or immunity from COVID-19. There are several trials ongoing that we hope will provide a range of antibody values post-vaccination and their relationship to immunity, but this information is not currently available. 

This is the breakdown of our recent results:


 % of test results
















As you can see the results are spread across the measurable range and above. However, we do not know the vaccination status or infection history of those we are measuring.

What does a positive result mean? 

A positive test result indicates that you have had an immune response to vaccination or the virus. Our test will also provide a numerical value that indicates the amount of antibodies. There is currently not enough data to indicate whether or not a higher number of antibodies indicates a stronger immune response or a greater level of immunity.  

What does a negative result mean? 

A negative result means that antibodies were not detected. This can indicate that you have not had a COVID-19 infection in the past or that antibodies have decreased to a level that can no longer be detected.

Can my test be positive because I have had a COVID-19 vaccine?

Yes, the COVID-19 vaccine immunity test measures SARS-CoV-2 S antibodies (spike protein antibodies). These antibodies can be made in response to any of the vaccines currently in use. A positive result can also occur from previous exposure to the virus that causes COVID-19.

If you have had a vaccine and would like to check if you have previously had the COVID-19 virus, you might want to get our combined COVID-19 Antibody and Vaccine Immunity Test. This test bundle can also tell you if you have previously had the COVID-19 virus.

Does a positive antibody test mean I am immune to COVID-19?

A positive test result indicates that you have had an immune response to vaccination or the virus. Unfortunately, a positive result does not mean that you are immune to the virus. It cannot tell you whether or not you can become ill with COVID-19 again. Nor can it tell you whether or not you can spread the virus to others. You should continue to follow all government guidance and restrictions.

Does this test tell me whether I have COVID-19 now?

No, this test does not tell you if you have a current COVID-19 infection. This test can only tell you if you have had COVID-19 in the past or an immune response to a COVID-19 vaccine.

If you have symptoms of COVID-19 that started less than eight days ago, then a PCR test can tell you if you have COVID-19.

How accurate is this test?

We use the Roche Anti-SARS-CoV-2 S test

Studies by the manufacturer have found that this test has a 98.8% sensitivity and a 99.98% specificity.

This means that:

  • The test might miss someone who has previously had the virus in approximately 1 out of 100 people (a false negative result).
  • The test might incorrectly be positive in 1 in 5000 people who have not had a vaccine or the COVID-19 virus (a false positive result).

We have performed our own verification to ensure that the test is fit-for-purpose and works with our home testing kits.

How does the COVID-19 vaccine immunity test work?

The test measures a sample of your blood to look for antibodies to SARS-CoV-2 spike protein (including IgG antibodies). The spike protein is produced by the virus that causes COVID-19. The spike protein is also used by all currently available vaccines to generate an immune response. The body responds to the virus or vaccine by making antibodies. These antibodies are used by your immune system to help fight infection. Peak antibody levels are typically seen 4-6 weeks after vaccination or infection.

Can this test be used as evidence for international travel?

No, the majority of international travel restrictions require you to take a COVID-19 PCR test prior to travel. This is to indicate that you do not have a current COVID-19 infection. A COVID-19 antibody test cannot be used for this purpose.

We do not issue certificates of results for either the COVID-19 Antibody Test or the COVID-19 Vaccine Immunity Test. Results will be available to view via our website.  

Some countries may waive quarantine restrictions for passengers with a positive COVID-19 antibody test. These tests must usually be conducted in a laboratory accredited by the country’s government.  For this reason, our COVID-19 Antibody Test and Vaccine Immunity Test cannot be used for this purpose.


"Turnaround time was impressive and I now know that the Pfizer vaccine has triggered an antibody response. As a clinically extremely vulnerable patient taking immunosuppressants for kidney disease, this gives me some confidence to slowly reintroduce myself into society. I was hesitant to use online services from private clinics but I knew you could be trusted when I saw you are run by the NHS."

Jeannie M.

How it works

Order a test online

Order a test online

All tests are confidential, and designed simply to help you self diagnose.

Home testing

Home testing

All tests are designed to be able to be carried out in the comfort of your own home, simply follow the package instructions.

Post it back to us

Post it back to us

For the best results all tests should be returned in the pre-paid package provided as soon as they are carried out.

See results online

See results online

We will contact you by your chosen method to let you know your results are ready (typically 24-48 hours following receipt of the sample). You will then be able to log into your personal dashboard and view your results.

Collecting your blood sample