There are so many different tests available for COVID-19 now. How do you know which one is right for you? This guide helps break down the main differences and what you can expect from each test. This information is rapidly changing, but we know that there are 2 types of tests currently available for COVID-19: a viral test and an antibody test.
Symptoms associated with COVID-19 may include:
If you are currently experiencing these symptoms, a viral test will determine if you have a current infection. Availability of viral tests may be limited depending on regulations from your state and local health department. Additionally, meeting testing criteria established by the CDC is necessary in order to get the test. According to the CDC, “Clinicians should use their judgment to determine if a patient has signs and symptoms compatible with COVID-19 and whether the patient should be tested.” (https://www.cdc.gov/coronavirus/2019-ncov/hcp/clinical-criteria.html)
It’s important to note that these symptoms may appear 2-14 days after exposure to the virus, and are usually mild and begin gradually. Some people who have the SARS-CoV2 virus that causes COVID-19 are asymptomatic and may not even know they have contracted the virus.
The COVID-19 viral test uses PCR technology to detect the genetic information that indicates whether an infection is active and that the virus is present. Samples of these viral tests are collected using a nasopharyngeal swab and are administered through a hospital or through your healthcare provider. It is possible for an individual to have a negative test result and yet still have very low levels of the virus.
If you think you may have had COVID-19 but do not currently have symptoms, an antibody (Serology) test will tell you if you had a previous infection. Antibody testing can check for different types of antibodies developed after exposure to the virus. It can take anywhere from 1 to 3 weeks after infection for an individual to make antibodies. It is still unclear if having antibodies to the virus can protect someone from getting infected again, or if you have antibodies, how long that protection will last.
These antibody tests are blood tests that detect antibodies (immunoglobulins, IgG and IgM) against the SARS-CoV2 virus that causes COVID-19. Antibodies are proteins that belong to the immunoglobulin class and are our body's immune system response to an infection.
IgG are antibodies that develop within 7 - 10 days after symptoms of COVID-19 begin. These IgG antibodies indicate prior infection of COVID-19 where your body developed antibodies that may protect you from future infection.
IgM are antibodies that are first produced by the immune system when a virus attacks. A positive IgM test indicates that you may have been infected and that your immune system has started fighting the virus. If IgM is detected, you may still have the active virus in your system.
Most antibody tests can test for both IgM and IgG, and can be ordered separately. These are blood tests where samples are taken through a finger-prick blood test or blood draw test.
How do you interpret results?
Check with your provider about their COVID-19 testing options and what may be the best next step for you.
TIP: Keep a record of any dates and locations where you believe you may have been exposed to COVID-19 or may have been in close contact with an individual with COVID-19. This will help with contact tracing to better contain the spread of the virus.