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Vaccines
 Understanding
  What Is a Vaccine?
  Vaccine Benefits
  How Vaccines Work
  Adjuvants and Other Vaccine Ingredients
  Types of Vaccines
 Research



Vaccines

Immune Cells

Illustration of immune cells responding to an invading virus
Most vaccines help prevent disease by mimicking the immune system's natural response to infection. In the body, cells called macrophages engulf invading microbes, such as viruses, and sound the alarm by showing pieces of the invader to T cells and B cells. B cells produce defensive molecules called antibodies that “stick” to the microbes, making them unable to multiply and cause disease. For more information, read How Vaccines Work.