Vaccination is one of the most effective ways to prevent diseases. A vaccine helps the body’s immune system to recognize and fight pathogens like viruses or bacteria, which then keeps us safe from the diseases they cause. Vaccines protect against more than 25 debilitating or life-threatening diseases, including measles, polio, tetanus, diphtheria, meningitis, influenza, tetanus, typhoid and cervical cancer.Vaccines are products that protect people against many diseases that can be very dangerous and even deadly. Different than most medicines that treat or cure diseases, vaccines prevent you from getting sick with the disease in the first place.