What COVID test do I need?

What COVID test do I need?

What COVID test do I need?

From 1st April 2022 the UK Government have stopped providing free COVID antigen tests to the general public. These are the tests that tell you if you have current infection at the time of testing.

Whilst there are some exceptions for who can still get free tests, which include the over 75’s and also the over 12’s with weakened immune systems, the vast majority of people now need to pay for their tests.

There is increasing suggestion that the pandemic has become endemic, but the question is  – Are we quite there yet? ( this is something we will cover in another blog!) The general view is that we are now learning to live with COVID so we each now have a personal duty to take control and test when it is deemed appropriate. But how do you know which test and when?

For many people there is a lot of confusion around the different types of testing. We get asked all the time.... so to try and simplify your options, we have provided a breakdown of the main tests available and what all those buzzwords actually mean.


What is an COVID-19 Antigen Test? – Am I currently infected with COVID-19?

An antigen test is a test that looks for current COVID-19 infection as it detects proteins that are present in the virus.

There are two main types - rapid tests, now commonly called lateral flow tests of "LFTs" that give you your result while you wait and PCR test which is where a swab sample is sent off to a lab.  

Both tests need a swab from the nasopharyngeal (back of the nose and throat) area, and a lot of lateral flow tests now need only and anterior nasal sample (from your nostril).

These tests have been used throughout the pandemic, mostly for symptomatic infection (you have symptoms of a COVID) but laterally were also used for asymptomatic infection (if you are infected with COVID-19 but don't have any symptoms).

As an antigen test is only for current COVID infections, they generally are only relevant for about the first 7-8 days from initial infection until the end of the virus lifecycle. PCR tests are more sensitive than lateral flow rapid tests and can generally detect infection earlier and perform better with asymptomatic infections, but they can also give positive results long after somebody is infectious. 

Those who experience ‘long covid’ are no longer infectious but still feel the after effects of the virus.


What is a Lateral Flow test?

A lateral flow test is quite simply any diagnostic test that flows laterally. The COVID-19 rapid home antigen tests are this style of device, but this technology was originally developed for home pregnancy testing. These style of tests require a sample mixed with a buffer solution, which flows laterally through the test strip and provides a result of negative (1 line) or positive (2 line) while you wait.

There are so many COVID-19 lateral flow tests on the market, with virtually all of them being manufactured in China. It is really important you only chose a self-test that has a CE mark with 4 numbers underneath it, as this means the test has been independently approved by a Notified Body. If it has a CE mark without any numbers underneath then it is the manufacturer who has awarded themselves the CE mark and it has not undergone any external scrutiny. 



What is a PCR Test – Am I currently infected with COVID-19?

PCR stands for polymerase chain reaction and actually detects the genetic material (RNA) of the virus.

Generally a PCR test requires a nasopharyngeal swab sample is taken, which many of us originally experienced through attending a drive thru or temporary COVID clinic before home sampling became available, which is then sent off to a laboratory.  The sample is then spun up to 40 times, which basically amplifies any of the RNA of the virus in the sample, so that it can be detected. This is why the test is so sensitive. 

You usually have to wait a day or two until you get your result, which will be either negative or positive.


What is a Fit to fly test?

For international travel, many countries needed a Fit to Fly certificate to prove somebody was COVID-free before flying. PCR testing was initially all that was accepted, but now lateral flow tests have also become acceptable proof.

The test usually is performed in a store or clinic, with the sample being taken by a trained person and the result being emailed back to you with a 'Fit to Fly Certificate' for you to show to your airline. Only UKAS approved organisations are able to provide these certificates, so always check the company you use is on the government approved list. You can click here.  

Many countries have now scrapped fit to fly tests, especially for vaccinated travellers but always check the country specific COVID testing requirements and guidelines before you fly! They can change quite quickly but just click here for the the most up to date info.


What is an antibody test? – Am I currently protected?

An antibody test needs a blood sample and detects the presence of antibodies which is what your body makes from having natural infection and/or vaccination. Antibodies are what protect you and there are different types of antibodies - some that fight off the virus (IgM) and others that remain in your body to protect you in the future (IgG).

To make it even more complicated, your body produces different types of IgG antibodies depending upon whether they were made as an immune response to infection or vaccination. 

There are two main types of antibody tests - rapid self-tests that need a finger prick blood sample and give you your result while you wait and more expensive lab-based tests where you will need to provide a large sample of blood 

Knowing whether you are protected post-vaccination or natural infection is now becoming the most desired test. It is widely publicised that antibodies decline over time and your level of protection is unique to you. The length of time you are protected can depend on many factors which could include your age, which vaccine you received and when, whether you have had a natural COVID-19 infection and your health status. Therefore, the only way to know whether you are currently protected is to test!

COVID-19 Antibody self-testing   

BioSure created the world’s first CE marked COVID-19 antibody self-test. It detects the neutralising IgG antibodies that your body makes from both natural infection and vaccination and these are the antibodies that give you protection against COVID-19.

The BioSURE COVID-19 IgG Antibody Self Test is very simple to perform, you  simply prick your finger using the paediatric lancet provided and then our unique device collects just the right amount into the tip - only a fraction of a drop of blood (2.5ul). 20 minutes later you will have your result. The strength of the line varies depending upon how many antibodies are in the sample.

Because it takes your body a little while to make antibodies, it is recommended to wait until 14 days after your infection of vaccination before using our test.


COVID-19 Antibody laboratory testing & home sampling

Some of these tests require a trained phlebotomist to take blood from a vein, but there are also laboratory based tests that can use capillary blood collected from a finger prick. To give you a comparison, the BioSURE COVID-19 Antibody self test requires 2.5ul of blood, but the lab test requires a minimum of 400ul. 

A collection kit is sent to you at home, you collect your own sample into a special vial and post it back to the lab. You generally get your results emailed a few days after you have posted your blood sample back.  

Depending upon the lab, it tests for different types of antibodies and will also give a quantitative result, ie it will say how many of each type of antibody you have. 

BioSure is pleased to offer you this home sampling option, as we know for some people this provides the peace of mind they need. It also provides a certificate, but as yet there are no countries that accept evidence of antibodies as part of their travel requirements. We hope that this will only be a matter of time, as many countries will accept evidence of past infection during the previous 6 months, and the only reason for this is that the person should have natural immunity during this time. 



Testing is still crucial to reduce the spread of the virus, provide peace of mind and help people make informed decisions and there are many options available to you so that you can take control.

BioSure is committed to providing you with simple, cost-effective, trust worthy solutions, so that you can make the right choices for you at the right time. They are delivered next-day to wherever you choose and there are a range of discounted product bundles so you can have tests to hand for whenever you need them.

If you need any more information or want to have a chat about any of our tests, please don't ever hesitate to get in touch. 


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