Comparison of PROs and CONs of Antibody Tests and PCR Tests

Click to see the comparison of the advantages between PCR and Antibody Tests

Click to see the visual comparison between two test methods

Advantages of the PCR tests:

 -       The disease can be diagnosed with the PCR tests from the start of the infection. In this respect, PCR tests are more reliable for early diagnosis of coronavirus.

-       The PCR tests directly examine the presence of the virus molecule in the body. In this respect, they provide higher accuracy in terms of determining positivity and negativity, when compared to the antibody tests.

-       Since they directly examine the virus molecules by replicating the molecules in the sample with advanced technology, PCR tests are more reliable in terms of the risk of confusing the coronavirus with other diseases, when compared to antibody tests. In this respect, they have higher level of specificity.

Advantages of the antibody tests (Covid-19 IgM/IgG rapid diagnostic tests):

-       -       Antibody rapid diagnostic tests provide results in just 10 or 20 minutes.

-       When compared to laboratory tests (PCR and ELISA), covid-19 rapid diagnostic tests are performed in a much shorter time with lower costs.

-       They can be applied wherever you are without visiting a special centre or laboratory just like glucose tests, minimizing the risk of infection.

-       The rapid spread of the coronavirus has made Covid-19 rapid cassette-type tests an urgent need in diagnosing the disease.

-       Antibody tests reveal both the presence of the virus and whether you previously had the disease.

-       Thanks to antibody tests, you can see if you previously had the disease and produced the necessary antibodies against it, even if did not show any symptoms during the disease.

-       Antibody tests detect healthy people who previously had the disease and provide the opportunity to give their blood to those struggling with the disease (Plasma Therapy).

-       According to studies, 40% of people infected with the coronavirus do not show any symptoms, while 50% of them have only mild complaints. For this reason, many infected people do not become suspicious for having the disease and need to have a test for it. In short, you may have had the disease free of symptoms and without realizing it. Antibody tests show you whether you have had the disease and if your body has already developed resistance to the coronavirus disease.

-       Rapid diagnosis is very important in the preventing the spread of the virus and rapid diagnostic tests allow much faster results, which is particularly important in the race against time required by infectious diseases such as the corona epidemic.

-       Just like glucose tests, Covid-19 antibody rapid diagnosis tests can be applied anywhere without the help of a specialist.

-       For all these reasons, coronavirus rapid diagnostic tests reduce the workload and congestion at healthcare environments such as hospitals, clinics and laboratories. In this way, they both keep those who suspect having the disease away from risky environments in such a period and prevent healthcare professionals from working in crowded environments involving the risk of contamination.

Disadvantages of the PCR tests:

-      -       PCR tests are only available at major hospitals as they require high cost device investments and they cause high test costs. It also costs a significant amount of money and time to deliver samples from surrounding cities and districts to these centres.

-       Finalization of PCR tests takes between 150 and 200 minutes after a sample is delivered to the laboratory.

-       Moreover, a single PCR device is able to study between only 8 and 24 tests during each test cycle of 150 to 200 minutes. Therefore, the test process is remarkably slow. In fast-spreading diseases such as the Covid-19, it is vital to get rapid test results for slowing down the transmission of the disease.

-       As a consequence, PCR tests are more difficult to implement due to the requirements of high cost technological facilities and specifically trained specialists.

-       Since the sample material is swabs in methods such as the PCR, samples are required to be taken by specialists. The reason why PCR tests may sometimes give false all around the world is that the swab samples are not always taken correctly.

-       In addition, the specialist needs to insert a stick into the patient's throat to get the swab sample required for the PCR tests, which means that healthcare professionals have very close contact with patients. This increases the risk of becoming infected for healthcare workers.

-       Many people who actually have from coronavirus disease do not want to enter in high-risk environments such as hospitals to have the test, since they do not experience any symptoms. This causes asymptomatic people to act comfortably in the community as potential infection sources.

Disadvantages of the antibody tests (serology tests):

-       Antibody tests are unreliable in the early identification of infections. Since they try to identify the antibodies produced by the body against the virus and not the virus itself, antibody tests are effective only after the production of antibodies against the virus. Such identification is only possible around 4 days after the onset of coronavirus disease in the body.

-       Since antibody tests try to identify the antibodies produced by the body against the virus and not the virus itself, it has the risk of interacting with antibodies other than the intended. Therefore, a test that interacts with any antibody may suggest positivity, which may be in fact not due to coronavirus, but a different defence antibody. Because of this phenomenon, cassette-type tests need to have high rate of specificity as one of their two most basic features. Antibody tests are more susceptible to giving “false positives” because they may miss the antibody that is specifically intended to be identified.

In Conclusion;

Rapid diagnostic test kits for coronavirus (Covid-19) antibodies and PCR tests are complementary to each other and both types of tests are vital.

Antibody tests are ideal for late infection screening and immunity monitoring, while PCR tests are ideal for early diagnosis of the disease.