When you are exposed to a new virus, your immune system creates proteins called antibodies to help protect you from infection. It may take your body weeks to start making the antibodies the first time it meets a virus. These antibodies can be made in large numbers if your body is exposed to the same virus again, which may help your body to defend itself against infection.
Because COVID-19 is a new disease, we don’t yet know if the antibodies you create can protect you from a future infection, or for how long this protection might last.
An antibody test, also known as a serology test, looks for specific antibodies in your blood. This test is useful because it shows if you have had the infection in the past, even if you had only mild symptoms. This type of test is less useful for diagnosing a disease because it can take some time for your body to make enough antibodies to show if you are infected.
To find out if you have COVID-19 right now, and are potentially infectious to others, you need a different test, called a viral test. Viral tests generally look for the presence of genetic material from the virus on swabs used to take a sample from your nose or throat. If positive, this determines that you are currently infected, and that you might be able to spread this infection to others.
Many companies have developed antibody tests for the virus that causes COVID-19. Health Canada has approved antibody tests for use in Canada, although these tests still need to be evaluated in more detail and are not yet available in BC.
BC researchers are studying antibody tests to determine whether they are useful for people in this province. Over the next while, they will learn more about the test, how it can be used, and how accurate it is.
Other research studies in BC and Canada are trying to understand whether people with antibodies to COVID-19 can get re-infected or can infect others. They are also looking at how many people have been infected with COVID-19 at a community-level.
Not yet. Until researchers learn more about the antibody test, it will not be offered in British Columbia.