Last updated: 26 October 2020
Boots has announced it will be offering a 12-minute rapid results coronavirus test, starting next month.
The test, which will cost £120, is billed by Boots as a convenient way for people to check for a current infection before travelling, attending an event or seeing family.
It involves taking a nasal swab which is then analysed on the spot.
The company says it is not suitable for people with symptoms or who think they might have COVID-19, who should seek a free test through the NHS.
While a swab test can indicate whether you were infected at the time of the test and provide some peace of mind, it is still possible you could develop COVID-19 soon after. It isn’t clear, either, what the false negative rate is for these tests.
NHS v private coronavirus testing
Currently, anyone in the UK can apply online for a coronavirus PCR swab test, which tells you whether you currently have coronavirus.
However, the past couple of months have seen lack of availability and serious backlogs affecting processing times for tests.
The most recent government stats show that the median turnaround time for home-test kit results in England is now up to 78 hours (up from 35 hours during July).
Despite the government testing woes, there appear to be a number of private clinics still selling coronavirus swab tests, either via a home test kit, clinician home visit, or clinic appointment (though some won’t see you if you have symptoms).
These tests are expensive: they are about £110-160 for a home test kit and up to £350 for a home visit.
Many of these providers appear to have availability, and estimates for results turnaround are between 24-72 hours. However, we don’t think anyone should have to pay out for a private coronavirus test if they need one.
It can be hard to verify the provenance and accuracy of these private tests, too: concerns have been raised about the way these tests are evaluated (for example with small sample sizes and/or in laboratory settings that may not reflect real life), and the quality of the trial data behind them.
The government has cautioned the public against taking any test that isn’t approved or verified – it’s important to at least check that the test is CE marked – but that means it needs to fix the national testing programme as soon as possible.
Antibody tests, which identify if you’ve previously been infected with COVID-19, are available to buy, but only if you pay to have blood taken by a healthcare professional.
We don’t think they’re currently worth it for the general public though. They are expensive and there are important limitations on what they can actually tell you.
Antibody tests where you take your own blood sample with a home finger-prick test are currently banned. This sampling process is being investigated by the Medicines and Healthcare Products Regulatory Agency (MHRA) to see if it’s viable.
It’s important to know the difference between the two tests, what’s available and what’s legitimate, as well as the limitations of what antibody testing can tell you.
Coronavirus testing explained
Get the lowdown on PCR vs antibody tests and what options are available to you:
- Getting tested for coronavirus
- How does testing and tracking work?
- Understanding your COVID-19 PCR test results
- What’s happening with antibody testing?
- Do antibodies mean you’re immune?
- Can you buy an antibody test?
If you think you have COVID-19
Diagnostic swab test
The PCR swab test, taken from inside the nose and / or mouth, indicates whether a person is currently infected with the virus.
This type of test takes longer to process as the samples need to be analysed in a lab.
Currently, anyone with symptoms can theoretically get a coronavirus test as part of the UK testing and tracking programs.
You can request this swab test online, and it can be done at a drive-through testing centre, at a mobile testing unit, or via a home-test kit. It tells you whether you’re currently infected with coronavirus.
It involves swabbing the inside of your nose and the back of your throat, using a long cotton bud.
You have to administer the test yourself and it can be unpleasant as the swab needs to go quite deep.
41% of Which? members who had taken this test said they found it difficult to do and patients have told us it can be easy to get wrong, especially when you’re feeling unwell.
Testing in hospital is available for patients and some NHS workers, and a new rapid results antigen test has been introduced in these settings.
The government website urges people to request a test as soon as they develop symptoms, and says testing must be done within the first five days of having symptoms.
If your test needs to be posted, you also need to allow time for it to arrive within that time.
You can book a test online through the NHS, though the availability of testing and length of waiting times has been fluctuating.
How does testing and tracking work?
The testing and tracking systems operate under slightly different guises across the UK. These are:
- England – NHS Test and Trace
- Scotland – Test and Protect
- Northern Ireland and Wales – Test, Trace, Protect
The basic steps for the testing and tracking systems operating across the UK are:
- Isolate – as soon as you have symptoms and for at least 10 days, while anyone you live with must isolate for 14 days from the onset of your symptoms
- Test – request a test as soon as possible
- Result – a positive result means you continue to isolate for the time set out above, if it’s negative you and anyone you live with can stop isolating
Share contacts – if you get a positive result, you will be contacted with instructions of how to share details of people with whom you have had close, recent contact and places you have visited.
How to tell if an NHS Test and Trace message is a scam – be alert for scammers taking advantage of the crisis
An NHS contact tracing smartphone app was supposed to form part of this system, but problems with the way it worked meant plans were scrapped in favour of a different version which is being developed with Apple and Google.
In Northern Ireland, people can download the StopCOVID NI app.
In Scotland, NHS Test and Protect has a Protect Scotland app.
Understanding your COVID-19 swab test results
NHS advice says you do not need to isolate if you receive a negative result, as long as everyone in you household or support bubble with symptoms also tests negative, and if you haven’t been told to isolate by NHS test and Trace.
Some doctors have raised concerns about the false negative rate for coronavirus testing, where your test is negative but you do actually have the virus, leading to possible false reassurance.
It is not known what the rate of false negatives is (a report in the British Medical Journal estimated it is between 2% and 29%), but a negative result from a swab test is conveyed to patients in very definitive terms – ‘you did not have the virus when the test was done’ – without any information about what might affect the result or its accuracy.
Government advice does tell people to continue isolating if you’re feeling unwell, even with a negative test result, so if you’re unsure, it’s best to stay at home.
There are also worries about the lack of information about an inconclusive test result, with patients simply being told their test is unclear and to apply for another one, but no information as to why this might be or how to avoid invalidating the test on another try.
If you receive an unclear result and you have symptoms, you must self-isolate for 10 days from the onset of symptoms, but if you don’t, you don’t have to self-isolate.
If you test positive, you must self-isolate for 10 days from when your symptoms started, or 10 days from getting your result if you are asymptomatic.
Anyone in your household or support bubble must also self-isolate for 14 days. In England and Wales, you should be contacted by NHS Test and Trace after testing positive. In Northern Ireland, you will be contacted by the PHA Contact Tracing service, and in Scotland, you’ll be contacted by the National Contract Tracing Service.
What about antibody tests?
Antibody tests are meant to show whether a person has already been infected with coronavirus. They work by detecting the presence of the antibodies our bodies produce to kill the virus.
Expanding accurate antibody testing would help experts understand how far the virus has spread, and how many people might have had it asymptomatically, or with mild symptoms.
How accurate are antibody tests?
Antibody tests are measured on specificity – which measures the proportion of ‘true’ negatives – and sensitivity, which measures the proportion of ‘true’ positives,
Jon Deeks, Professor of biostatistics at the University of Birmingham, says that while a positive result is fairly definitive, a negative result is less certain.
Professor Deeks explains that antibodies might not present as strongly in people with mild or no symptoms and studies so far have mostly been done on patients with severe cases – so this could skew the data for how accurate the tests are.
Still plenty of unknowns around COVID-19 immunity
It is hoped that once someone has had COVID-19, they are immune to the disease, but crucially, this is still uncertain.
The presence of antibodies in your blood can tell you you’ve been exposed to the virus, and therefore can also offer some information about how you reacted to it, but at the moment that’s about it.
The World Health Organisation (WHO) says: ‘We expect that most people who are infected with COVID-19 will develop an antibody response that will provide some level of protection. What we don’t know yet is the level of protection or how long it will last.’
It warned against making assumptions about a person’s immunity to coronavirus based on antibody testing. A positive result can’t yet be interpreted as a stamp of immunity, and there have been some suspected incidences of reinfection.
Any level of immunity can only be assumed in the short term because we just don’t have long-term data yet on how this virus behaves.
The Advertising Standards Authority (ASA) has banned some advertising from private clinics including the London Vaccination Clinic, Solihull Health Check Clinic and the Corona Test Centre London for claiming that a positive antibody test would show that people were immune to the disease.
Antibodies or T-cells?
Antibodies are also not the only way to gauge immunity from a disease. T-cells (a type of white blood cell) also play a role in the body’s immune response by mobilising the body’s defense mechanisms and destroying infected cells.
Researchers have discovered a T-cell response to coronavirus in people who didn’t have antibodies, but more research needs to be done in this area.
Can you get an antibody test?
The The Medicines and Healthcare products Regulatory Agency (MHRA), an executive agency of the Department of Health and Social Care, says that antibody tests ‘should only be performed and interpreted by fully trained, healthcare professionals and not by members of the public.’
So, some private companies such as Qured, Medichecks, DocTap and Forth are offering to send a healthcare worker to your house to administer the test, or selling antibody tests along with an in-person doctor’s appointment. This generally costs about £85-£130 per test.
We don’t think it’s worth spending money on an at-home coronavirus antibody test currently, as there’s a risk that they could give a false sense of security, and they can’t tell you much right now on an individual level.
It’s important to note that you should continue to follow government advice around social distancing regardless of an antibody test result.
Beware of antibody self-testing kits
Home antibody tests that you do yourself with a finger-prick blood sample have been banned while the methodology they use is investigated.
Companies supplying these tests – which did include Superdrug – have been asked by the MHRA to stop selling them for now.
These tests require you to take a blood sample by pricking your fingertip, and sending the blood off in a vial to be analysed at a lab. What the MHRA is looking into is the process of taking a blood sample from your fingertip at home, and whether samples collected in this way will yield accurate results.
Be wary of any company selling an antibody test you can administer yourself. The Royal College of Pathologists has recently written to the Health Secretary Matt Hancock urging tighter controls on antibody self-tests after discovering that these were still being sold online illegally.
No home test kits for coronavirus where you conduct the test and instantly get a result at home can legally be sold in the UK.
For now, the best thing you can do is follow the social distancing guidelines and guidance on how to protect yourself and others.
This story was originally published in March 2020 but has been regularly updated to reflect new information and rules around testing.