COVID-19 Testing Protocols
According to the U.S. Department of Health and Human Services/Centers of Disease Control and Prevention (CDC) the COVID-19 (Coronavirus Disease-2019) can cause mild to severe respiratory illness. The virus normally causes an infection in your nose, sinuses, or upper throat and can be severe and is classified as such; Severe Respiratory Syndrome (SARS). SARS-CoV-2 is different from the six other, previously identified human coronaviruses, including those that have caused previous outbreaks of Severe Acute Respiratory Syndrome (SARS) and Middle East Respiratory Syndrome (MERS). Both MERS-CoV and SARS-CoV have been known to cause severe illnesses in people, however the complete clinical picture with regard to COVID-19 is not fully understood.
Exposure to COVID-19
COVID-19 is believed to be spread from person-to-person, primarily through respiratory droplets produced when an infected person coughs or sneezes. The virus is also believed to be spread by people touching a surface or object and then touching one's mouth, nose, or possibly the eyes. People are thought to be contagious when they are most symptomatic (i.e., experiencing fever, cough, and/or shortness of breath). Some spread might be possible before people show symptoms; there have been reports of this type of asymptomatic transmission with this new coronavirus, but this is also not thought to be the main way the virus spreads. Older people and people with compromised immune systems and underlining health conditions seem to be at a greater risk of serious illness.
What is an antibody? And why are there different types?
An antibody is an immunoglobulin and is part of our immune systems response to a foreign molecule or pathogen and/or antigen. Our immune systems response is valuable because it helps fight off infection. More protective antibodies can provide long-term immunity in some cases so that we don't become re-infected with the same virus or bacteria. Developing such antibodies can be instrumental for our health. It is also important to know that some people do not always develop antibodies (or the right antibodies) to fight off all infections.
Overall, there are five main classes of antibodies. The three classes usually associated with infectious disease serology testing include IgG, IgM and IgA.
Understanding Antibody IgG Results
Detection of IgG antibodies may indicate prior exposure to COVID-19. For the most accurate results, it is recommended that COVID-19 antibody testing be performed at least 10 days after potential exposure to COVID-19 or the onset of symptoms, to allow for the complete development of IgG antibodies. The IgG antibody test provides insight into an individual's immune response after exposure to COVID-19, but it is not intended for diagnosis of active infection. It is recommended to consult with a physician for appropriate testing if you believe you have an active infection.
What is the difference between a Molecular PCR vs Antibody test?
As opposed to the antibody test which is generally detecting the body's immune response in the form of antibody presence, Molecular PCR tests are used to directly detect the presence of the virus itself. This means that a PCR test can tell whether someone has been infected with virus very early on. An antibody test can approximately tell us what proportion of the population has been infected, but it won't tell you who has been infected since the presence of the antibodies are not generated for a week or two after symptom onset. See Levels of Detection chart.