If there is one red line visible next to the "C" in the KnowNowᵀᴹ device test results window, and any line at all, no matter how faint, appears next to the "T", then the test result is positive. This indicates that the SARS-CoV-2 antigen has been detected in the sample.
Following a positive result, current government guidance on matters including self-isolation and reporting the result should be followed.
So that we adhere to the strict rules around lateral flow tests, we have to make sure that anyone activating a sample pack is doing so purely to learn more about KnowNow Testing, and not as means of administering a clinical test.
The KnowNowᵀᴹ Test's specificity is 99.9%. In more than 300 negative patient saliva samples, it hasn’t returned a single false positive result.
This is so important for getting life back to normal. We don't want anyone to be stopped from going to work, heading off on holiday or socialising at events, when actually it would be perfectly safe for them to do these things.
Specificity is particularly important when disease prevalence is low and tests are intended to be used at enormous scale. For example, if a test with just a 3% false positive rate is used on one million people per day, that would result in 30,000 people per day being falsely identified as infectious with COVID-19 and being unnecessarily asked to self-isolate.
There have been questions raised around the sensitivity of rapid lateral flow antigen testing for SARS-CoV-2 as compared to PCR testing. However, these questions have been strongly challenged by the scientific community.
PCR tests identify the presence of the SARS-CoV-2 virus in the body, regardless of whether the virus is actively infectious. The PCR testing process amplifies the genetic code of the virus so that even minuscule amounts of the virus in the sample can be picked up. This makes for a powerful test, but since viral fragments can linger in the body for weeks even after the infection has cleared, infected individuals being tested using PCR will show as positive for a median period of 22–33 days in total. On the other hand, most people infected with SARS-CoV-2 are contagious only for 4–8 days.
So whilst PCR testing for SARS-CoV-2 may have been considered the "gold standard" test up until now, it will by definition show different results when compared to lateral flow tests which aim to identify individuals based on viral loads which suggest they are within their infectious window. This discrepancy between what each test is actually testing for has caused some issues where PCR testing has been used to evaluate the effectiveness of lateral flow tests, such as in the mass testing rolled out in Liverpool in November 2020.
The KnowNowᵀᴹ Test goes a step beyond other lateral flow tests with its unique, patented detection mechanism which only shows a positive result when live infectious virus is identified in the sample. As a result, PCR tests will similarly show different results to the KnowNowᵀᴹ Test in certain cases, since they will show positive results even for individuals outside of their infectious period.
For a much more comprehensive and referenced answer, you may like to read "Clarifying the evidence on SARS-CoV-2 antigen rapid tests in public health responses to COVID-19" from the Lancet.
At the moment, KnowNowᵀᴹ Tests are for professional use only, meaning that they need to be administered by a trained healthcare professional. This means that we can take orders from organisations that have in-house or outsourced healthcare professionals who can perform the tests, or testing service providers.
However, since the KnowNowᵀᴹ Test needs just a saliva sample, it is much easier to administer effectively than other similar tests, and still return highly sensitive results. So we are investigating whether specially-trained, competent individuals could be approved to administer KnowNow tests as well.
We are also in the process of trialling and seeking approval for a variation of the KnowNow test which could be administered by individuals themselves.
We’re focused on developing our predictive health technology and tests so that we can make medicine more proactive and help to predict illness before it becomes acute or infectious. We want to empower people to feel in charge of their own health and wellbeing by making testing more readily accessible and available, allowing for earlier prediction and prevention of acute illnesses.
So that the KnowNowᵀᴹ Test is used as effectively as possible, it currently needs to be administered by a trained healthcare professional.
A trained healthcare professional is defined by the Medicines and Healthcare products Regulatory Agency (MHRA) in the Target Product Profile for Point of Care SARS-CoV-2 Detection Tests as a professional belonging to one of the 10 health and social care professional bodies that are overseen by the Professional Standards Authority. You can find a list of these professions here.
However, since the KnowNowᵀᴹ Test needs just a saliva sample, it is much easier to administer effectively than other similar tests, and still return highly sensitive results. So we are investigating whether other specially-trained, competent individuals could be approved to administer KnowNow tests as well.
We are also in the process of trialling and seeking approval for a variation of the KnowNowᵀᴹ Test which could be administered by individuals themselves.
We're so pleased that you'd like to order our KnowNowᵀᴹ Tests. At the moment we are running some pilots with a few key partners, before distributing our tests more widely.
Please fill in our form and our team will get back to you.
The KnowNowᵀᴹ Test is the UK's only on-the-spot COVID-19 test that uses just your saliva to tell you if you are currently able to infect someone else with COVID-19.
Unlike other tests, the KnowNowᵀᴹ Test won't give you a positive result if you have been exposed to the SARS-CoV-2 virus in the past, but are no longer able to infect other people.
Although vaccine rollout is progressing extremely quickly in the UK, the government expects that it will be the end of July 2021 before every adult in the UK has been offered their first dose of a COVID-19 vaccine. Second doses should be received around 12 weeks after the first, and so it is likely to be the end of October 2021 before every adult has received both doses.
In the meantime, whilst we await full vaccine rollout, regular rapid antigen testing offers a way to enable the re-opening of society.
Beyond this, it is also important to consider that no vaccine is 100% effective even after 2 doses, that not everyone will accept or be able to have the vaccine, and that there is uncertainty as to whether the vaccines will work effectively against current or future mutations of the virus. We should also consider the fact that the UK is very much ahead of other countries around the world in progressing its vaccine rollout, and that it will still be some time before the vast majority of people globally will be vaccinated.
With these factors in mind, regular testing is likely to play a role in keeping societies safe and open for some time to come.
What’s important when it comes to sensitivity is how much virus needs to be present in the patient sample for the test to give a positive signal. This is known as the 'Limit of Detection', and we measure this rather than clinical sensitivity as it is much more informative.
Our Limit of Detection is between 50,000 and 200,000 viral copies per mL, making our test more sensitive than other rapid antigen tests available. The Abbott BinaxNow test, for example, needs 1,000,000 viral copies per mL in order to get a positive signal.
The KnowNowᵀᴹ Test's low Limit of Detection means it can detect infected people as early as day 3 to 4 of infection. This is before they become highly infectious, and a day or two earlier than most tests available (based on models of viral load in disease progression).
If you'd like to read more about this subject, we recommend reading this paper. It argues that the "Limit of Detection matters and directly impacts efforts to identify, control, and contain outbreaks during this pandemic" since "higher LoD are likely to miss nonnegligible fractions of infected individuals." It also makes the case that Limit of Detection values for tests using universal standard metrics should be readily available in the public domain to enable like-for-like comparison.