By now, you’ve probably heard about the race to develop a vaccine to cure the novel coronavirus that’s wreaking havoc all over the world. In the meantime, the best way to slow the spread and flatten the curve is to test whenever and wherever possible.
Some tests check for active infections, but others check for the presence of an old virus in the body; two of these are antigen and antibody tests. These tests are often confused for each other, though they’re two entirely different items. So, what’s the difference?
Antigens are molecules that are capable of inducing a response in the body’s immune system; usually, they serve to trigger illness or decline in physical condition. By contrast, antibodies are proteins created by the body in response to encountering antigens. In other words, antigens can come from viruses, while antibodies are developed to fight off sickness. By testing through different methods, doctors are able to determine whether or not a patient has had the coronavirus with more certainty and clarity.
Antigens and antibodies also have a role in vaccine development. When creating a vaccine, antigens are used to stimulate the antibodies in the patient to respond to the disease in question, thus developing a level of immunity. The antibodies then remain in the body for a certain period of time, usually years, to defend against future iterations of the disease.