Scientists Say: Vaccine

This is a substance given to people to help them develop immunity to a disease

a photo of a young man after getting a shot

Vaccines help a person’s body fight off illnesses.

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Vaccine (noun, “VACK-seen”)

This is a substance that can give a person immunity from a disease. That means their body can recognize and kill disease-causing organisms before they can start an infection. Many diseases are caused by bacteria or viruses. Some vaccines are made with a whole virus that has been killed or made harmless. Others contain materials that imitate part of a disease-causing agent. These materials are all antigens. Antigens trigger the immune system to respond.

A vaccine introduces these antigens to the bloodstream. The body recognizes that the antigen is an intruder. The immune system responds, producing antibodies. Later, if the person is exposed to the actual virus or bacteria, the antibodies recognize it. These tiny proteins glom on to the antigen. This helps the body recognize and destroy the virus or bacterium before anyone gets sick. 

There are vaccines for viruses such as measles and mumps. There are also vaccines against some bacteria, such as the one that causes whooping cough.

In a sentence

Scientists are trying lots of new methods to make a vaccine against the new coronavirus. 

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Bethany Brookshire was a longtime staff writer at Science News Explores and is the author of the book Pests: How Humans Create Animal Villains. She has a Ph.D. in physiology and pharmacology and likes to write about neuroscience, biology, climate and more. She thinks Porgs are an invasive species.

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