Immunization shots, or vaccinations, are essential. They protect against things like measles, mumps, rubella, hepatitis B, polio, diphtheria, tetanus and pertussis (whooping cough). Immunizations are important for adults as well as for children.
The Centers for Disease Control and Prevention defines the flu as a contagious respiratory illness caused by influenza viruses. The flu can cause mild to severe illness, and at times can lead to death. The best way to prevent seasonal flu is by getting a seasonal flu vaccination each year. Particular populations such as older people, young children, pregnant women and people with asthma, diabetes, or heart disease are at increased risk for serious complications from seasonal flu illness.
Your immune system helps your body fight germs by producing substances to combat them. Once it does, the immune system "remembers" the germ and can fight it again. Vaccines contain germs that have been killed or weakened. When these vaccines are given to a healthy person, the vaccine triggers the immune system to respond and thus build immunity.