What Is Serology Testing for COVID-19?


Posted October 21, 2021 by beauty33

COVID-19 is an infectious disease caused by SARS-CoV-2 infection, which has caused more than 200 million cases and 4 million deaths worldwide as of August 2021.
 
COVID-19 is an infectious disease caused by SARS-CoV-2 infection, which has caused more than 200 million cases and 4 million deaths worldwide as of August 2021. To better control the outbreak, serology testing can be used as one of the diagnostic bases for confirmed and suspected cases.
When a virus invades the body, it produces specific antibodies as a defense, with specific IgM antibodies being the first to be produced for early defense, followed by IgG antibodies. Serology testing is used to indirectly detect the existence and level of specific antibodies IgM and IgG in blood samples to determine if there are viruses and viral infections in the body.
“Both IgM and IgG belong to the immunoglobulin family, which is a class of serum active components produced by plasma cells that bind specifically to antigens when the body is stimulated by antigenic substances,” as introduced by a scientist at Creative Biolabs, a biotech company focusing on non-IgG antibody in disease diagnosis.“According to their molecular structure and antigen specificity, immunoglobulins are divided into IgG, IgA, IgM, IgD, and IgE.”
In general, after being infected by a virus, the body produces a series of modifications to defend against this invasion—after the initial entry of the antigen into the body, plasma cells are produced and antibodies are synthesized and secreted after a certain latency period. The first to appear is IgM, but this antibody is short-lived and disappears quickly, lasting from a few days to a few weeks in the blood. The next to appear is IgG.
IgG is the main component of immunoglobulins and is the only immunoglobulin that can pass through the placenta. The level of IgG peaks and persists in the blood for a longer period of time when IgM is close to disappearing. When exposed to the same antigen again after months or even years, the antibody content increases rapidly in the short term and may be several to tens of times higher than that of the first time, dominated by IgG, which also lasts for a long time in the body. At present, researches on COVID-19 patients showed that IgM antibodies take about 5-7 days to be produced after the virus invades the body, and IgG antibodies 10-15 days.
During this period, IgM and IgG cannot be detected in serum, which is when nucleic acid testing is advantageous—it can detect infection in patients in the window period.
Compared with serology testing, nucleic acid testing can detect patients in the window period and identify infected patients early. While blood specimens for serology testing are more guaranteed, the operation is simple and fast, and the risk of infection of medical workers during specimen collection and testing is largely reduced. If nucleic acid detection of viral ribonucleic acid (RNA) is the direct evidence of the existence of the virus, the gold standard; then antibody detection is the indirect evidence, the indispensable assistant.
The Centers for Disease Control and Prevention (CDC) has already suggested a strategy for using serology testing as part of surveillance efforts to better understand how much of the U.S. population has been infected with SARS-CoV-2 and how the virus is spreading through the population over time.
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Issued By www.creative-biolabs.com
Country Armenia
Categories Biotech
Last Updated October 21, 2021