Antiserum vs. Antibody — What's the Difference?

Antiserum is a blood serum containing antibodies against specific antigens, used to confer immunity to infectious diseases or to treat venomous bites or stings. It is produced by injecting an animal with an antigen and then collecting the serum, which contains antibodies specific to that antigen. On the other hand, an antibody is a protein produced by the body's immune system when it detects harmful substances, called antigens. Each type of antibody is unique and defends the body against one specific type of antigen.

Antiserum works by providing passive immunity, immediately offering protection against specific pathogens or toxins without waiting for the body to produce its own antibodies. This makes antiserum useful in emergency situations where rapid response is necessary. Conversely, antibodies are part of the body’s active immune response, taking longer to develop but offering targeted protection and longer-lasting immunity once they are produced.

The production of antiserum involves the introduction of antigens into a host animal, leading to the generation of antibodies in the host’s blood. After a period, the serum containing these antibodies is harvested. Antibodies, however, are generated directly by the immune system’s B cells in response to the presence of antigens, without the need for an external serum.

Antiserum can cause allergic reactions or serum sickness due to the introduction of foreign proteins into the body. Whereas, antibodies generated within an individual’s body are less likely to cause adverse reactions since they are naturally produced by the immune system.

The use of antiserum is limited to specific contexts, such as snake bites or severe infections where immediate immunity is necessary. Antibodies, on the other hand, are fundamental to the body’s ongoing defense against a wide range of pathogens and are continuously produced in response to infections or vaccinations.