About the COVID-19 rapid antibody test

Here you can find questions and answers regarding the rapid antibody test. Together we fight COVID-19 – don’t hesitate to get in touch for further information.

What is Noviral’s rapid antibody test?

Noviral’s rapid test is a combined IgM-IgG antibody test for COVID-19 used to qualitatively detect the presence of IgG and IgM antibodies by the new human coronavirus using a few drops of either serum, plasma, or whole blood.

How safe is the test?

It should be pointed out that no tests are 100 percent and we collect more and more data to have additional evidence on the test’s accuracy.There are studies in the Uppsala research team on precisely our tests with larger control panels (more samples) to secure the numbers more and more.However, at this point we can conclude that the Noviral’s rapid tests are of a very high standard.A study conducted at Uppsala University, in collaboration with the Academic Hospital in Uppsala, showed that the specificity of the test is 100% for IgM and 99.2% for IgG. The study is published and can be provided here. A further evaluation, with a quantitative so-called “gold standard”, which can determine which of the positive samples from the study actually had detectable IgM and IgG antibodies respectively, shows extremely strong sensitivity with 100% for both IgM and IgG. The results thus look very promising and this test has stuck out in quality compared to other similar antibody tests in several studies from different countries.

What is antibody rapid test sensitivity?

The sensitivity is the proportion of people infected with COVID-19 and identified through the Noviral’s antibody rapid test through a positive test result. Simply put, the sensitivity is an estimate of the tests ability to detect those who have had COVID-19.

A low sensitivity increases the risk of false negative results, which is that the test does not detect all those with antibodies. Failing to detect those with antibodies could possibly lead to people having had COVID-19 unknowingly.

What is antibody rapid test specificity?

A test’s specificity is the proportion of healthy people with negative test results through Noviral’s antibody rapid test. A high specificity is important as an unspecific test could increase the risk of invalid results. That in turn could result in a false sense of security and a worst-case scenario where individuals believe they have antibodies and therefore could act in a health hazardous way that could increase the risk of getting infected.

A test’s specificity can be estimated by testing large numbers of samples collected and frozen before SARS-CoV-2 is known to have circulated to demonstrate that the test does not produce positive results in response to the presence of other causes of a respiratory infection, such as than other coronaviruses.
The more samples used to validate a test, the smaller the confidence interval becomes, meaning that we can be more confident in the estimates of sensitivity and specificity provided.

Is the rapid test FDA approved?

By May 2020, the rapid test has US FDA approval by the Food and Drug Administration.

The test is also CE Certified. CE marking is a product marking in the EU and the European Economic Area (EEA). The letters CE are the abbreviation for Conformité Européenne (‘in accordance with EC directives’). A product with CE marking may be sold in the EEA area.

Conducting the rapid test

How is the test conducted?

First, a healthcare professional takes a blood test, a stick in the finger. Next, the blood sample is added to a sample container, along with 2 to 3 drops of a buffer solution. The test answers can be read within 15 minutes. It shows if you have IgM and/or IgG or none. For a more detailed description, please see the instructions enclosed with the test.

Why do healthcare professionals need to perform the test?

Because the test result needs to be interpreted and analyzed correctly. More parameters than just the test result need to be included in the analysis and the recommendation going forward. For example, symptoms showed since the start of 2020. In addition, the CE marking of the test is only valid if the test is carried out by a healthcare professional.

How long does the rapid test take to show the test result?

Compared to laboratory tests, the test answers can be read within 15 minutes.

When in the course of the infection should Noviral’s rapid test be performed?

Since it takes time to develop antibodies to a new virus, the sensitivity of the test is lower during the first days after the symptoms appear. The accuracy and reliability increase with time from the first symptom and a test should not be performed prior 14 day post the first symptom. This has been confirmed in previous studies and also in the knowledge base presented by the Public Health Authority. The Public Health Authority states that it usually takes one to two weeks from the beginning of the symptoms for an individual who is immunologically naive to develop an antibody response to a new virus. They also mention that antibody tests performed during the first two weeks after first symptom presentation, may require re-testing at a later time to obtain a reliable test result, especially as the affinity of the antibodies (i.e., binding to the virus) is expected to increase over time. Therefore, Noviral recommends that a rapid test should be taken after at least 14 days from the first signs of symptoms.

RT-PCR Test Graph

Figure 1. The graphs above illustrate when COVID-19 infected persons are expected to test positive by 1. PCR during the first two weeks of the disease (from samples taken from the throat/nose). Over time the virus gradually disappears as the disease clears (green line) and PCR testing becomes less reliable.  The illustration also shows how 2. COVID-19 infected individuals develop antibodies over time (red line) over the course of an infection. The graphs illustrate that it is more reliable to measure antibody responses first 2 weeks or more after initial symptoms were recorded. You are likely most contagious just before and during the first few days of having symptoms.

Interpretation of the result

How do I know if the test did not work?

The card on the test contains a control line (C). Regardless of the antibodies that exist in the sample, the C line should go from blue to red to indicate that the sample has been adequately moved through the membrane. If the C line does not change color, it indicates that the test result is invalid. Repeat the test procedure with a new test cartridge.

Is the test result is a response to infectiousness?

No. The response from Noviral’s antibody test should not affect the susceptibility assessment. Instead, the test aims to answer the question of whether a person has developed antibodies to COVID-19 or not. To know which people should isolate themselves or not, we recommend  you read “How can we reduce the spread of infection” via this link (in Swedish) that is available via the Public Health Agency.

Have I had COVID-19 infection if only lgM comes back positive but not lgG?

According to the Public Health Agency’s knowledge base on serology for COVID-19, data support that IgM can persist after symptoms have declined and thus IgM positive persons can exist without having active disease. Thus, an IgM response does not necessarily indicate that the person has an active viral infection. The IgM response is currently difficult to interpret and therefore we recommend that a pure IgM response is supplemented with either a PCR test if possible and/or a new antibody test after another week to evaluate if the person is undergoing a general immunological process and also develops a positive IgG response. This is also confirmed in the knowledge base from the Public Health Agency, where they write that “The diagnosis of COVID-19 positive antibody response should not be based solely on IgM positivity, but must be verified with IgG seroconversion in a follow-up test”.

According to the Public Health Authority’s knowledge base, they describe that “It is likely that the majority of infected persons seroconvert one to three weeks after symptom onset and exhibit an IgG that can be demonstrated by tests with a good performance “. This also confirms our guidelines that Noviral’s rapid test should be taken at least 14 days after the onset of symptoms.

Is it certain that a person who has a positive IgG response is immune?

If the patient has recently undergone a coronavirus infection and is testing positive for IgG, he/she has most likely developed an immunity (protection against the virus). This is also confirmed in the Public Health Authority’s knowledge base for serology for COVID-19 where they write that “a measurable IgG response is likely to provide some or even complete protection in case of re-infection. There are no convincing studies yet that humans can be infected a second time shortly after a first disease period.” Furthermore, results from studies in Finland, the Netherlands and China demonstrate neutralizing antibodies in patients who have undergone a COVID-19 infection, supporting a plausible immunity, albeit transient, to SARS-CoV-2, similar as reported from the SARS-CoV-1. There are reports that some individuals do not develop antibody responses, if these individuals have acquired for example T cell immunity is not yet established but is highly likely.

How long could a potential immunity towards COVID-19 last?

It is still unclear how long you are immune, how big the differences are between individuals, and whether genetic drift of the virus, in the long run, affects long-term immunity. Based on current research (of other viruses), the assessment is that the immunity lasts at least for so long that one will not be infected multiple times within one season. We will update this document regularly as new information on immunity to COVID-19 is published.

Purchase information

Why don’t we sell to private individuals?

The testing needs to be done by health care professionals, meaning people with formal education in health care or medicine. An important reason for this is that the CE marking of the test is only valid for use by healthcare professionals. Furthermore, the test needs to be used properly and the test result needs to be interpreted and analyzed in combination with other parameters such as type of symptoms and when they were evident.

How long is the delivery time?

At present, the delivery time is 5-7 days, but this may change. What we can certainly say is that we try to deliver the tests to you as soon as we can.

What is the minimum order?

The minimum orders are 100 pcs. Of course, we want to be able to help small business owners too. Therefore, you are welcome to contact us even if you need less than 100 tests, so we will try to link your order with other small companies so you can place a joint order.

What is the maximum order volume?

For large orders, please contact info@noviral.se. Please specify which order volume you want to order.

Who is behind noviral?

See “About Us“.

The Q&A below will be updated on an ongoing basis, based on new recommendations from authorities and new research available.
Last updated: 2020-06-02