An antibody test is a blood test to check if you’ve either:
- had coronavirus (COVID-19) before
- made antibodies to the virus after having the COVID-19 vaccine
An antibody test is different to the swab test to check if you have COVID-19 now. You can get a test to check if you have COVID-19 now on GOV.UK.
What an antibody test can tell you
An antibody test can tell you if it's likely you've had COVID-19 before. It checks if your body has created antibodies to the virus or if these are from the vaccine.
Some people who’ve had the virus or the vaccine do not have antibodies. This means the test does not work for everyone.
An antibody test does not tell you:
- if you're immune to COVID-19
- if you can or cannot spread the virus to other people
You can still catch and spread COVID-19, even if you've had the virus before or been vaccinated. It’s important to follow advice about how to avoid catching and spreading COVID-19.
Getting an antibody test
The test is not available to everyone yet.
You can get a free antibody test if you:
- did a PCR test for COVID-19 and had a positive result
- work in primary care, social care or education
- are taking part in research
Doing an antibody test after a positive PCR test result
Anyone booking a free PCR test for COVID-19 on GOV.UK can also opt in to get an antibody test.
If you opt in and your PCR test result is positive, you may be sent 2 antibody tests to do at home.
You’ll need to do the first antibody test within 6 days of getting your positive PCR test result. You’ll need to do the second test about 3 weeks after the first test.
You can still have the antibody test if you've had the COVID-19 vaccine.
Doing an antibody test after a positive PCR result helps the NHS learn:
- how likely people are to get COVID-19 again
- how the body’s immune system responds to the virus or vaccine
If you're unable to get a free antibody test, you can pay to have a test at a private clinic if you want to.
How an antibody test works
The test checks for antibodies in your blood.
Your body makes antibodies when you get an infection. They help fight the infection.
If you have COVID-19 antibodies in your blood, it's likely you've had the virus before or had the COVID-19 vaccine.
It's not known if having antibodies stops you getting the virus again.
What an antibody test involves
You'll need to do the test at home.
You'll receive the test kit in the post. Read the instructions in the test kit carefully.
You'll need to prick your fingertip using a device called a lancet and squeeze some blood in a tube.
You can get someone to help you if you’re nervous about doing the test, unless you’re self-isolating.
You’ll need to post your completed test kit in a Royal Mail priority postbox.
Important: If you’re self-isolating
You can leave your home to post your blood sample.