Vaccines help the body’s immune system recognize and fight viruses or bacteria. They prepare the immune system to respond more quickly and effectively if exposed in the future. Because vaccines use small amounts of weakened or inactive germs, they do not cause the disease they protect against.
Vaccine studies may involve:
• Understanding immune response • Evaluating safety • Measuring protection against illness • Supporting development of new vaccines
Vaccines currently protect against many serious diseases, and continued research is important for improving public health.