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COVID-19 Antibody Testing Explained

Frequently asked questions about COVID-19 antibody testing.

Written by Dr Adam Abbs. Last updated 15/03/2021.

What are the different types of COVID-19 tests?

  • PCR - A swab is used to take a sample from the nose or throat. This is analysed for viral fragments. It detects current or recent infection. These are the most accurate tests available.
  • Lateral Flow / Rapid Antigen Tests - These tests give results within minutes. They look like a pregnancy test and are used to detect current or recent infection with Covid-19.
  • Antibody Blood Test - This looks for evidence of past infection with Covid-19.

What are antibodies?

Antibodies are produced by the body to protect against infections. Following an infection, these antibodies stay in the blood to help protect it against the same infection in future. Antibodies that protect against Covid-19 are usually detectable after the first few weeks following infection and last for months, but research into this is still ongoing. Even if someone doesn’t suffer from symptoms of Covid-19, they will still normally produce antibodies.

What is a COVID-19 antibody test?

The test looks for antibodies to the SARS-CoV-2 virus (the virus of Covid-19). If found, it indicates that you have had Covid-19 previously. If no antibodies were detected, either you haven’t had Covid-19, or you have had it and your antibodies have worn off. Antibody tests cannot be used to diagnose Covid-19, but can indicate if someone has had it in the past, although not in the first few weeks following infection (Source)

How do you perform an antibody test? 

You prick your finger with a special device and then bleed a few drops into a bottle. These drops are then tested for the presence of antibodies to see if you have developed an immune response to the virus. 

Antibody testing is generally painless and involves a small blood sample which is then sent to a specialised lab for antibody testing.


How can I get an antibody test?

Antibody tests are not widely used currently. Free antibody tests are currently only available for certain people who work in healthcare, social care or education. These tests are to help the NHS and scientists learn more about who has already had the virus and how it has spread in the UK. You can find out if you are eligible for a free antibody test here

Who can get an antibody test?

The rules for who can register for an antibody test depend on your age, job and location.

  • If you’re in England you can only register for a test kit if you’re 18 or over and you work in paid adult social care. 
  • If you’re in Wales you can only register for a test if you’re 18 or over and you work in paid domiciliary care (caring for people in their homes). 
  • If you’re in Northern Ireland you can only register for a test if you’re 18 or over and work in primary care or adult social care.
  • If you’re in Scotland you can only register for a test if you’re 18 or over and working in education.

Why should I take an antibody test?

Taking the test helps the NHS and research scientists learn more about who has had the virus and how it is transmitted.

Antibody testing has been designed to aid the NHS and research scientists in uncovering more about the disease.


I think I have symptoms, is an antibody test the right test for me?

Antibody tests cannot be used to diagnose a current Covid-19 infection. It can take 1–3 weeks after getting the infection for your body to make antibodies. If you think you may have Covid-19 symptoms you must follow the current government guidelines, which include isolation for you and your household, and a Covid-19 PCR test 

Does the presence of antibodies mean that a person is COVID-19 immune?

There are many studies underway to better understand the antibody response following infection to Covid-19. Several studies to date show that most people who have been infected with Covid-19 develop antibodies specific to this virus. However, the levels of these antibodies can vary between individuals and over time. (Source)

How useful are antibody tests?

Antibody tests can only indicate that someone has had Covid-19 previously, and may help our understanding of the virus and it’s transmission.

Are there any risks associated with having an antibody test?

There are no specific risks related to taking this type of antibody test. Taking a sample of blood in this way is incredibly safe and it scratches only for a second. This doesn't require blood directly from a vein. (Source)

Test Results

How long does it take to get an antibody test result?

This will depend on your test provider but typically you should receive your antibody test result within 3 to 7 days of taking the test.

What should I do after receiving my result?

Regardless of your antibody test result, you must continue to follow national guidelines to protect yourself and others from the virus: wash your hands often, follow social distancing and face covering advice, follow any local lockdown restrictions in your area and follow the rules on when to get tested and when to self-isolate.

Regardless of your antibody levels, if you develop symptoms for Covid-19 at any point (fever, persistent cough, altered sense of taste or smell), then you must apply for a PCR test and self-isolate until the results are known.

What does a positive test result mean?

A positive result means that the test detected coronavirus antibodies so it is likely you have had coronavirus before (even if you can’t recall having symptoms). IgG antibodies suggest that your infection was recent. IgM antibodies suggest your infection was over a few weeks ago. 

If I test positive am I protected from Covid-19?

No. You may have some protection, for a period of time following infection. But we don’t yet know what degree of protection you will have, or how long that lasts. So you still need to follow social distancing rules.

What does a negative result mean?

A negative result means that the test did not detect coronavirus antibodies so you are less likely to have had coronavirus yet. It is possible to have had the virus and receive a negative antibody result. This can happen because someone doesn’t produce enough antibodies, or they have worn off after some time. (Source)

What should I do if my test result is void?

A void result means that the test did not work. There are many potential reasons for this and it is likely not possible to tell you the exact one.

Can I ignore lockdown restrictions if I test positive for antibodies?

No. There is no evidence yet to say that if you have already had the virus you are immune. You should continue to follow all the government guidelines. (Source)

How will my test result be used?

Your result will be made anonymous so that there is no link between your test and personal information such as your name. Results from across the country will provide information about the prevalence of Covid-19 in different regions. This will help organisations like Public Health England to better understand how the disease spreads. (Source)

Where can I get a private antibody test?

If you are unable to get a free antibody test on the NHS, you can pay to have a test at a private clinic. More information about this can be found here.

Does Medicspot offer a private antibody test?

Medicspot does not currently offer a private antibody testing service. 

Travel and antibody testing

Can I travel if I have tested positive for antibodies?

You must follow government guidelines that currently advise against all non-essential travel whether or not you have tested positive for Covid-19 antibodies. You will also need to speak to your airline and destination country for the rules that they have.

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