Scientists, researchers, and investigators alike all across the world are currently on the hunt for a test to identify signs of recovery from this novel coronavirus that is currently causing a pandemic. In order to identify individuals who have recovered from COVID-19, a test must be administrated that identifies certain antibodies of SARS-CoV-2 that are circulating in the blood stream of the recovered individual. A test to this liking has recently been created and approved by the US Food and Drug Administration, and its purpose is to not identify an active infection, but to identify individuals who have experienced this infection and have built up an immunity to it, through new antibodies. This blood test is also known as a serology test, in which it looks for specific components of an immune response to demonstrate that the individual has been infected by the virus and thus received immunity from it. The immunity built up from being infected from the virus is generally characterized by the presence of IgG and IgM antibodies that are specific to the virus in question.
Immunoglobulin M is the first antibody to be generated from an infection of an unknown virus, and serves as the first line of defense among the adaptive immune system. If a person had a serology test performed and a titer was positive for only IgM antibodies, this would mean that the individual had a recent infection of COVID-19, as there wasn’t enough time for IgG antibodies to develop. Immunoglobulin G antibodies are the second antibody to develop from a novel infection, and are primarily sources for future immunity. This means if an individual has a titer positive for both IgM and IgG, this shows that have had a recent infection, but it has been a couple of weeks since there is IgG present in collaboration with IgM. If a titer results in IgG antibodies being present without IgM antibodies, a period that is later in regards to the course of infection would be portrayed.
A titer that presents positive results for the presence of IgG and not IgM, clearly portrays that the individual had an infection in the distant past and now has an immunity built up to that particular virus. This is because IgM has a shorter half-life than IgG, which allows IgG antibodies to make up the immune response and allow for a defense against future encounters with the particular virus. Ultimately, if a person results in a positive titer for IgG, this would mean that they have an immunity against the virus, and will be able to be exposed to the virus and not get a corresponding infection. By testing the public for IgG antibodies specific to SARS-CoV-2, public health officials will be able to identify what percentage of the general population has been infected with COVID-19 and the levels of corresponding immunity. By having a positive titer of IgG antibodies specific to SARS-CoV-2, the individual cannot necessarily become infected with the virus or spread it, thus allowing these specific individuals to ultimately return to “normal” life.
ImmuniTEA Spill 