COVID-19 (SARS-CoV-2) IgG Antibody
Molecular testing (PCR Swab) will identify people with the virus. Antibody testing can tell whether a person has been previously infected. Most patients who recover from coronavirus have been found to produce antibodies, but it is not yet known if an individual with a positive result showing presence of IgG levels following being infected with SARS-CoV-2 will be protected, either fully or partially from future infection, or for how long protective immunity may last.
Testing should be undertaken 14 days or more following exposure or onset of symptoms. The incubation period of COVID-19 ranges from between 1 to 14 days, with the majority of cases manifesting with symptoms at 3 – 5 days. The most common symptoms of COVID-19 are fever, tiredness, dry cough and difficulty breathing. These symptoms have the potential to develop into a very severe acute respiratory illness. Evidence shows that fatality rates increase with age, gender, body weight, ethnicity and comorbidities.
The host immune system reacts to the infection by SARS-CoV-2 by producing antibodies from a few days to 2 weeks and beyond. Specific IgG antibodies are produced in the later stages of infection to SARS-CoV-2, and are detectable after RNA is no longer detectable.
The persistence of IgG antibodies allows identification of people who have been infected by SARS-CoV-2. Test development relating to SARS-CoV-2 is rapidly evolving. Laboratory review of new assays as they become available is essential.