COVID-19 antibody test: How is it different from the current nose and throat swab tests?

At present most of the COVID-19 testing is done by collecting swab samples from the suspected patients. But they don't always give satisfying results. The new test is expected to improve detection of the infection. Read to know how.

Now, COVID-19 infection can be detected through a blood test. A newly launched lab-based serology blood test specifically identifies the antibody immunoglobulin G, or IgG, a protein that the body produces in the late stages of infection. Launched by US pharma giant Abbott Laboratories, the antibody test will help identify if a person has had the novel coronavirus as well as gauge how long protective antibodies last within the body following an infection. It is expected that such tests will provide a deeper understanding of the virus's spread, and help support the development of treatments and vaccines.

This antibody test will initially be available on Abbott's ARCHITECT i1000SR and i2000SR laboratory instruments. These instruments can run up to 100-200 tests per hour. Currently, more than 2,000 of these instruments are in use in US laboratories. But the company has plans to expand the test's use to its newer line of Alinity instruments

Further, the device maker plans to distribute 4 million antibody tests within the next two weeks and speed up its production to 20 million tests per month beginning in June.

Abbott's third COVID-19 test

This is the third COVID-19 test launched by the same company. Its two COVID-19 tests are already being used to detect coronavirus patients. These include its m2000 molecular laboratory system and its ID NOW molecular point-of-care device. The later consists of a small, tabletop box capable of scanning swab samples for the novel coronavirus's molecular signature and can provide a result in less than 20 minutes. Thanks to its portable nature, the testing kit can be deployed anywhere in case of an emergency.

At present most of the COVID-19 testing is done by collecting swab samples from the suspected patients. But they don't always give satisfying results. Sometime, the results may not turn up positive even if the person has (or had) COVID-19.

Coronavirus nose and throat swab tests

A swap test for COVID-19 starts by extracting sputum from a person nose or throat. It is then tested for the presence of some of the coronavirus' tell-tale genes. Here lies the loophole. If the virus isn't living in the spot from where the sputum was collected, the infection may not be detected. Again, if the sample isn't collected properly, the test could still come back negative. This is the reason why many COVID tests come negative even when the person actually has the virus.

Real-time RT-PCR

The most common kind of coronavirus test being used now is real-time RT-PCR (reverse transcription polymerase chain reaction). The test can deliver a diagnosis in three hours, but usually laboratories take on average between 6 to 8 hours. Compared to other available virus isolation methods, real time RT-PCR is considered to be faster and more reliable. So far it continues to be the most accurate method available for detection of the coronavirus.

But the test is only designed to detect the ongoing infection, it can't test past infections or if you had COVID-19 in the past. This is because viruses are only present in the body for a specific window of time.

Now, the new blood test has made it possible. The Abbott's antibody test can determine who's had the virus, even if they never had the coronavirus symptoms. This will help in understanding the development and spread of the virus as well as support the development of treatments and vaccines.