Antibody testing has been one of the most talked about topics during the COVID-19 pandemic (also known as the Coronavirus pandemic). How do antibody tests work? Will an antibody test confirm whether I have COVID-19, or if I’m immune? Are antibody tests safe and accurate? How do I even get an antibody test? Right now it might feel like there are more questions than answers.
We’re here to explain more about the work that goes on behind the scenes in developing an antibody test.
Research & Development
It’s important to remember that COVID-19 is a novel pandemic. This means that information is constantly developing as scientists learn more about SARS-CoV-2, the virus that causes COVID-19.
Although point-of-care antibody tests are simple and fast to perform, it can take a long time to develop one that is accurate and effective. The Research & Development teams behind an antibody test first need knowledge of the proteins that form the outer layers of the virus, its “protein coat”. Specifically, they need to know which proteins cause your body’s immune system to respond by producing antibodies. Learn more about antibodies at our Q&A.
Once they have selected the sections of the virus’ protein coat that will work for the test, scientists have to produce them in the laboratory. They’ll be used in an antibody test like INSTI, which detects whether your body has produced antibodies to SARS-CoV-2, therefore showing that you were infected with the virus. This process can be complex and takes time. Plus, with scientists around the world looking to develop a COVID-19 antibody test, it’s not surprising that samples of these proteins can be difficult to access.
Accuracy
When bioLytical decided to develop an antibody test for COVID-19 one of the most important criteria was to ensure high accuracy.
The two key features for the accuracy of any test are sensitivity and specificity. A test has to be sensitive enough not to miss the antibodies if they’re actually present, but specific enough not to accidentally show a positive result.
An antibody test such as INSTI works like a magnet, using parts of the virus (the sections of “protein coat”) to attract antibodies and pull them to the test dot to show a result that can be easily read and understood. This magnet needs to be precise, because otherwise the antibodies found in your blood could stick to it too. If other antibodies stick to it, you will get a false positive result.
Why Antibody Testing?
Antibody tests provide evidence that an individual was exposed to the virus. The information provided by these tests is helpful for scientists to better understand immunity against the virus and how it spreads, helping them to make informed decisions that impact the health of the population.
What we don’t yet know is the level of immunity provided by antibodies to SARS-CoV-2, the amount of antibodies required to provide protection, or how long that protection lasts. Put simply by the BBC’s Health & Science Correspondent, James Gallagher, “There are no guarantees that if you have antibodies against the coronavirus that you are completely immune.”
The first use of antibody testing in countries around the world will be in wide-scale testing, helping experts to understand the effects of COVID-19 on the wider population and make public health decisions accordingly. For example, an antibody test could help authorities to understand how prevalent the disease is, and how many people have been infected but are asymptomatic. It could also help identify potential donors of “convalescent plasma,” an approach in which blood plasma containing antibodies from a recovered individual serves as a therapy for an infected patient with severe or immediately life-threatening disease.
What’s next?
bioLytical’s INSTI test is currently being validated by external researchers and clinicians. Authorities including FDA, Health Canada and the World Health Organization continue to review new antibody tests for COVID-19, with the FDA recently updating their policies to ensure greater accuracy among tests submitted for their approval.
In a recent Atlantic article, James Hamblin, M.D., explained that although we may not know all the implications of COVID-19 antibody test results yet, they are still an important part of any response to the pandemic:
“There are always questions about exactly how many antibodies are required to prevent an infection, and how long they last. We act based on averages and best estimates across populations. But at an individual level, none of us is suddenly rendered invincible. We may only ever be able to say that, for example, 80 percent of people who have a positive coronavirus antibody test are truly adequately protected. But when the prevalence of disease falls—because so many of us have been sick, or get vaccinated, or simply practice good hygiene—that number becomes enough to effectively protect us. In keeping with the recurring theme of this pandemic, we’re all in this together.”
