A guide to COVID-19 tests: latest update

This guide, updated 15 October, will help you to understand the different types of test now available, how they work and how to get one.

 

Virus tests

These tests (sometimes called ‘swab’ or ‘antigen’ tests) check to see if you are currently infected with the virus.  The swab is taken from your nose and throat or alternatively, a saliva sample might be used.

The ‘swab’ sample is collected from the nose, mouth, and/or throat. A swab is a small piece of soft, absorbent material on a plastic stick.

Some virus tests use saliva samples, collected into a small container, to check for the virus. However, this type of sampling is not yet done routinely in the UK.

You may collect swab and saliva samples at home yourself (this can also be referred to as ‘self-sampling’), or you can get a healthcare professional to do it. The sample is then sent to a laboratory to check for genetic material from the virus.

Swab self-sampling kits are currently being rolled out at scale by the government to anyone with symptoms. You can access self-sampling kits through the NHS test and trace programme.

Antibody tests

These tests check for antibodies to see if you have had an infection with the virus in the past. This test requires a blood sample.

Antibody tests are currently only offered to NHS and care staff, as well as some hospital patients and care home residents. They can also be bought privately, but it’s important to be aware of their limitations.

Some antibody test kits require a blood sample from a vein, which can only be collected by a healthcare professional or qualified person.

Other antibody test kits require a smaller amount of blood to be taken. This type of sample is taken from a capillary via a finger prick blood sample. In certain cases, you may be required to then put this sample on special paper to dry – this is known as a dried blood spot (DBS). When only a small amount of blood is required, you may collect the blood sample at home yourself, or you can get a healthcare professional to do it.

Both types of blood samples are sent to a laboratory to check for antibodies.

These tests are not used for diagnosis but rather to give the NHS a better understanding of the prevalence of the virus in different places.

Sample collection kits

For both virus and antibody tests, a sample is taken from you and this sample is then tested in a laboratory by a trained professional to see if you have the virus or have had it in the past.

A sample collection ‘kit’ is the name given to the different parts of a COVID-19 test that help obtain a ‘sample’. This kit must have a valid CE mark to show that the manufacturer has met the minimum safety and performance requirements for the product.

The sample you have to provide, and whether or not you can collect that sample yourself, will depend on what type of test you are having.

Self testing

A self-test kit is one in which you take a sample, test it yourself, and then read and interpret the results yourself as well. This is different from self-sampling where the sample is taken at home but then sent to a laboratory for testing.

There are currently no COVID-19 self-test kits in the UK suitable for home use and it is illegal to supply them for use by members of the public. This is because no COVID-19 self-test kits have a CE mark. However, this may change if CE marked self-test kits become available.

Limitations of testing

No test is 100% reliable, even those with valid CE marks. The results are also only relevant to that sample at that point in time.

It’s important to understand the limitations of COVID-19 tests, because an incorrect or misinterpreted result can lead to a false sense of reassurance. For example, if you are infected with the virus but the test you use produces a false negative result (it says you do not have the virus even though you do), you may unknowingly spread the virus to other people or not seek the treatment you may need.

How to get a test

Virus tests are available via the NHS Test and Trace programme. They may also be provided by some UK employers, occupational health and other private healthcare providers.

Antibody tests are currently only offered to NHS and care staff, as well as some hospital patients and care home residents. They can also be bought privately. However, it’s important to be aware that the General Pharmaceutical Council have advised pharmacies not to offer rapid antibody testing.

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