Antigen, Antibody, or PCR: What to Know About COVID-19 Testing

Our experience with the novel coronavirus has made a number of terms more common in our vocabulary these last several months. For example, terms like ‘rate of transmission,’ ‘viral load,’ and even ‘antigen’ are certainly trending, and with good reason. Scientists believe educating the public with the key vocabulary can improve their ability to make intelligent choices about their health. Additionally, it helps alleviate common misconceptions about COVID-19 testing and how we develop our methods. Now more than ever, a reliable and accurate test has become a vital aspect of the nation’s COVID-19 defense. We’ve seen this impact affect families across the nation, and even impact the White House.

Back in March when COVID-19 broke into the headlines, one of the country’s greatest concerns was creating an accurate testing method to determine rates of contraction. The novelty of the Sars-COV-2 virus meant that very little research had been done to create a comprehensive and accurate test. Fortunately, around the world scientists were working quickly to rectify that. Very quickly, PCR testing using the virus’s genetic code (via RNA) became the gold standard across the world.

But as questions on immunity have arisen, many scientists have also developed alternative methods that measure a person’s level of viral antigens or antibodies produced.

Currently, there are three methods for COVID-19 diagnostic testing.

In this article, we will discuss the difference between the three, and why Integrity Laboratories is confident in our ability to accurately and reliably assess your results with the best PCR technology on the market.

What are Antigens and Antibodies?

Antigens are molecules that work to stimulate an immune response. They can be made from a variety of biological compounds such as lipids, proteins, nucleic acids, and polysaccharides. Each antigen expresses very distinct and unique features that interact with our immune system.

Antigens can be found on animal cells, bacteria, and viruses. For the Sars-COV-2 virus, many antigens are commonly shared with other members of the coronavirus family. Although new to humans, several well-known antigens have been thoroughly documented from previous research to correspond with the novel strain.

Antigen tests have been widely considered effective at determining infection. Their presence is only positive if the virus has been contracted, and disappears as the virus disappears. However, as some of these antigens share a common ancestry, their lack of sensitivity to the Sars-COV-2 strain can lead to false-positive results. In addition, these analyses have been shown to be time-consuming in comparison to antibody and PCR testing.

Continuing the trend, antibody tests were also developed by analyzing an individual’s immune response to the virus. When our immune system confronts an unfamiliar antigen not from our own cells (like that of an invading virus or bacteria), our body preps for war. The creation of a corresponding antibody, a ‘Y’ shaped protein produced by the immune B cells, works like a ‘key’ to a specific antigen ‘lock’ to help immune cells identify pathogens. These B cells generate antibodies and attach them to the outside of the immune cell membrane. When they confront another cell, they temporarily connect to determine ‘friend or foe.’ If the corresponding antigen isn’t present, the B cell moves on. However, if the key connects with the right lock, the B cell unlocks its impressive defensive mechanisms to consume and digest the pathogen whole. In some cases, they may even ‘tag’ them to be destroyed by other aspects of the immune system.

covid-19 testing

The ‘Y’ shaped antibodies are deployed to identify and interact with specific antigens on the Sars-COV-2 virus.

Antibody tests are equipped to measure if an antibody is present in your blood, suggesting your body has come in contact with COVID-19 and has developed an immune response to the virus. Although reliable when a response is present, it can take your body quite some time to develop an adequate response that can be measured. Previous studies have suggested that peak immune response from IgM to Sars-COV-2 could take upwards of 2 weeks after infection, followed by IgG antibody at 3 weeks. Unfortunately, taking an antibody test too early post-infection might produce a false-negative result. Those that would benefit from an antibody test may be those who have already tested positive and wish to follow their immune response to monitor their condition. Recently, we’ve seen these mixed results illuminated by the current White House predicament. Despite daily testing, the antibody diagnostic test failed to accurately assess the levels of COVID-19 among White House staff.

Why PCR Testing Remains the ‘Gold Standard’ for COVID-19

As research continues to help us develop specialized technology to combat COVID-19, the public requires access to accurate testing.

This is why we at Integrity Laboratories continue to offer best in class diagnostic testing for infectious diseases. Our methods, using our Intercept-PCR technology, specifically uses the genetic code of Sars-COV-2 to accurately and reliably test for the presence of the virus. By focusing on specific RNA sequences associated with the virus, we are not hindered by generalized or time-consuming strategies. Our methods are met with incredible accuracy to provide families within our region rapid results. We’re cutting down the time and reducing the rate of inaccurate testing by offering access to our state of the art technology.

At Integrity Laboratories, we aren’t just confident in our facility and methods. We are also profoundly fortunate enough to have a team of specialists and technicians that stay up-to-date with the research. We assure you we’re offering the best service and best technology to get you the answers you need to keep you and your family safe.

Integrity Laboratories began testing for SARS-CoV-2 (COVID-19) under Emergency Use Authorization (EUA) on March 23.

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