The race for a Covid-19 vaccine: vocabulary to know

Adaptive (or Acquired) Immunity: Immune response (such as activation of T-cells or antibodies) that occurs after the body has previously been exposed to an unknown or foreign substance, like a virus or bacteria.

Adjuvant: A substance added to a vaccine that helps it boost the body’s adaptive immune response to a pathogen like a virus or harmful bacteria.

Antibody: A Y-shaped protein important in the body’s adaptive immune system. Antibodies can recognize and neutralize foreign substances, like a virus. Vaccines help stimulate the body’s antibody response.

Antigen: A molecule that is recognized by the body as foreign (like proteins on the surfaces of viruses), and can provoke an immune response. Some vaccines use antigens from a target virus to help the body produce an immune response.

Clinical Trial: A clinical trial is a study evaluating the safety and effectiveness of a new drug, vaccine, or medical procedure in humans.

Clinical Trial, cont'd: There are four stages or “phases” of clinical trials, starting with a small number of test subjects and increasing that number through Phase IV. At each phase, safety and effectiveness are carefully tracked.

T-Cell: A type of lymphocyte or white blood cell that targets infected cells and destroys them. (Another type of T-Cell, called a Helper T-cell, stimulates other parts of the immune system)

Vaccine: A substance that stimulates the body’s immune system, creating an adaptive immunity to a known pathogen.

Live Attenuated Vaccine: A type of vaccine that uses a weakened form of the target virus to help the immune system build up an adaptive immunity.

Subunit vaccine: A type of vaccine that uses just a portion of the target virus, like an antigen, to help the immune system build up an adaptive immunity.

Viral Vector Vaccine: A type of vaccine that uses a harmless live virus to carry DNA into cells. The DNA codes for the antigens of the target pathogen, so when the antigens are produced, the body learns to recognize and fight them..