Had COVID - 19 symptoms in the last 2 days? Apply here to help us make testing accessible to all.
back to all FAQs

Is KnowNowᵀᴹ approved and safe?

The KnowNowᵀᴹ test has been developed to Vatic's stringent standards of quality and safety.

It has undergone the necessary clinical trials and performance tests and has been shown to meet the specific requirements published by the UK's Medicines and Healthcare Products Regulatory Agency (MHRA).

The KnowNow test has been CE marked for professional use in a healthcare setting and has been registered for use in the UK and the EU.

Is it necessary to perform multiple tests to be sure of the result?

It should not be necessary to perform more than one test on a given individual at a single point in time, unless the KnowNowᵀᴹ device test results window displays no lines at all, meaning that the test has failed, or unless it was not possible to read the test results within 15 to 60 minutes of applying the mixed saliva and buffer solution to the KnowNowᵀᴹ device.

However, receiving a negative result does not mean that the individual tested can't be exposed to the SARS-CoV-2 virus following the test. So we do recommend that individuals are tested regularly to keep workplaces and communities safe. Depending on the scenario, we would recommend testing is repeated every 1 to 3 days.

How does KnowNowᵀᴹ compare to COVID-19 antibody tests?

The KnowNowᵀᴹ Test and COVID-19 antibody tests test for completely different things.

Antibody tests identify whether someone has had coronavirus in the past, whereas the KnowNowᵀᴹ Test detects whether an individual is currently infectious.

Antibody testing involves detecting the immune response in the human body to having fought off a virus. These tests look for an antibody created in the bloodstream in response to the presence of a virus in that environment. This is useful when testing the effectiveness of a vaccine, or understanding how far and wide a virus has spread. However, it is of limited usefulness to individuals, as it is only able to identify whether an individual has fought off the SARS-CoV-2 virus in the past. It cannot effectively confirm whether they are currently infected, or infectious.

What does a negative test result look like and mean?

Negative KnowNowᵀᴹ Test Result

If there is one red line visible next to the "C" in the KnowNow device test results window, and no line at all next to the "T", then the test result is negative. This indicates that no SARS-CoV-2 antigen has been detected in the sample.

How is a KnowNowᵀᴹ Test administered?

There are just 4 simple steps to the KnowNowᵀᴹ Test.

  1. Swab the mouth: The KnowNowᵀᴹ Test requires just a saliva sample to be taken easily and comfortably from the mouth. We know how uncomfortable and painful other lateral flow antigen tests or polymerase chain reaction (PCR) tests can be, with swabs going high into nostrils and all the way back to tonsils. It was really important to us that people would feel happy to take a KnowNow test on a regular basis.
  2. Shake the tube: The saliva swab is placed into a buffer solution in a small tube, and shaken up to mix it well.
  3. Squeeze on panel: A few drops of the mixed solution is squeezed onto the KnowNowᵀᴹ Test device.
  4. Know in 15 minutes: It takes just 15 minutes for the positive or negative result to appear in the test result window on the KnowNowᵀᴹ Test device. No need to wait 24-48 hours for results, as you would with a PCR test.

I've already activated my sample pack

If you have already activated your sample pack please go to the activation link that we emailed to you. Alternatively, if you fill in your email again we will re-send the activation link to you.

Where do you make your KnowNowᵀᴹ tests?

KnowNowᵀᴹ Tests have been invented, developed and manufactured in the UK.

How specific is the KnowNowᵀᴹ Test?

The KnowNowᵀᴹ Test's specificity is 100%. In more than 700 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.

How accurate are your tests?

COVID-19 test accuracy is typically determined by ‘specificity’ and ‘sensitivity’.

Specificity is about the extent to which you can eliminate false positives; sensitivity is how much virus needs to be present before a test picks it up. So there is always a need to strike a balance, when testing, between trying to pick up the virus as early as possible, versus accidentally delivering a positive test result for someone who is not actually infected.

The specificity of the KnowNowᵀᴹ Test is 100%. In more than 700 negative patient saliva samples, we haven’t had a single false positive.

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 very 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 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.

How soon after exposure would the KnowNowᵀᴹ Test give a positive result?

The KnowNowᵀᴹ test will show a positive result from day 3 or 4 after exposure to the SARS-CoV-2 virus. This is earlier than other rapid antigen tests, which usually start to show positive results around day 5 or later.

This also means that individuals will receive a positive KnowNowᵀᴹ test 1 or 2 days before they are at very high risk of infecting others. So where there is a regular testing programme in place, individuals can quickly be isolated before they become highly infectious and the spread of the virus can be prevented.

The basis for this is our analysis of models of viral load in disease progression, such as the one shown within "Test sensitivity is secondary to frequency and turnaround time for COVID-19 screening" by Dr Michael Mina et al, alongside the low limit of detection of the KnowNowᵀᴹ test of 50,000 to 200,000 viral copies per mL.

Is there a limit to how frequently I can take your tests?

No, there's no limit at all. KnowNow is specifically designed for frequent testing in order to offer the best chance of identifying infectious individuals as early as possible.

We recommend that individuals are tested as regularly as possible to keep workplaces and communities safe. Depending on the scenario, we would recommend that testing is performed every 2-3 days, or even daily, depending on the scenario.

Had COVID - 19 symptoms in the last 2 days? Apply here to help us make testing accessible to all.