Serological antibody screening tests for COVID-19 currently include ELISA, LFIA, and CLIA methods with the ELISA technique the most commonly used. (For more details on these methods please refer to the previous sections).
It is important to note that for commercial application a variety of serological tests are cost-effective, convenient, and more efficient than the RT-PCR detection for COVID-19 identification. Moreover, the development of effective and reliable serological detection methods plays a vital role in monitoring the abundance and neutralization efficiency of antibodies in infected patients, evaluating and predicting the severity of symptoms of patients, and quantifying the quality of immune response to new vaccines.
Although Antibody tests are not used to screen for active COVID-19, the most common current uses for antibody tests include:
Testing individuals with persistent symptoms of COVID-19: Individuals who have had symptoms of COVID-19 for several weeks may not have an active infection that is detectable by antigen or molecular testing (PCR). Therefore, in these individuals, an antibody test may suggest a prior SARS-CoV-2 infection which could explain symptoms and support a diagnosis of COVID-19.
Testing people with late-developing complications of COVID-19: Since the health effects of COVID-19 can develop weeks or months after an infection, an antibody test may help to identify a previous infection and explain an individual’s delayed symptoms of coronavirus infection.
Epidemiological and research studies: Antibody tests can provide useful information to better understand COVID-19 such as helping to estimate how many people have been infected. Antibody tests can also be used to try to determine how past infection affects the risk of developing COVID-19 in the future.
