Immunization protects against the following 10 serious diseases (infections) that can cause disability and death. These diseases used to strike thousands of children each year. Today there are relatively few cases, but outbreaks still occur each year because some babies are not immunized.

     Except where noted, these diseases spread when viruses or bacteria pass from an infected person to the nose or throat of others.

1. Diphtheria

     This serious disease is spread by bacteria or germs. Diphtheria can cause blockage of the airway, making it impossible to breathe. It can also cause heart problems.

2. Tetanus (lockjaw)

     Tetanus is caused by a toxin (poison) produced by a germ that enters the body through a cut or wound. Tetanus causes serious, painful spasms of all muscles and can lead to "locking" of the jaw so a person cannot open his or her mouth, swallow, breath, or move. Three of 10 people who get tetanus die from the disease.

3. Pertussis (whooping cough)

     Pertussis is caused by bacteria. It can cause spells of violent coughing and choking, making it hard to breathe, drink, or eat. The cough can last for weeks. Pertussis is most serious for babies, who can get pneumonia, have seizures, become brain damaged, or even die. About half of the babies who get pertussis have to go to the hospital.

4. Polio

     Polio is caused by a virus that is spread by contact with the feces (bowel movement) of an infected person. Symptoms can include sudden fever, sore throat, headache, muscle weakness, and pain. Polio can cause paralysis and death.

5. Measles

     The measles virus is spread very easily. Even being in the same room with a person with measles is enough to catch the disease. Symptoms include a rash, fever, cough, and watery eyes. Measles can also cause pneumonia, brain damage, seizures, or death. Of every 1,000 children who get measles, 1 or 2 will die from the disease.

6. Mumps

     The mumps virus causes fever, headaches, and swollen salivary glands under the jaw. Children who get mumps may develop mild meningitis (inflammation of the covering of the brain and spinal cord) and sometimes encephalitis (inflammation of the brain). Mumps can also result in permanent hearing loss.

7. Rubella (German measles)

     The rubella virus usually causes a mild sickness with fever, swollen glands, and a rash that lasts about 3 days. But if a pregnant woman gets rubella,she can lose her unborn baby, or the baby can be born blind, deaf, mentally retarded, or with heart defects or other serious problems.

8. Hib Disease

     Haemophilus influenzae type b (Hib) bacteria causes meningitis. It can also cause pneumonia and infection of the blood, joints, bone, throat, and heart covering. This disease is very serious for children younger than age 5, especially infants.

9. Hepatitis B

     Hepatitis B is an infection of the liver caused by a virus. It spreads through contact with blood or other body fluids. This can happen through sexual contact or by sharing a razor, toothbrush, or needles used to inject drugs. Hepatitis B causes a flu-like illness with loss of appetite, nausea, vomiting, rashes, joint pain, and jaundice (yellowing of the eyes and skin). An infected pregnant woman can expose her newborn to this virus during birth. The virus stays in the liver of some people for the rest of their lives and can result in severe liver diseases or cancer.

10. Varicella (chickenpox)

     The varicella virus usually causes a rash, itching, tiredness, and fever. It can lead to pneumonia, brain infection, or death. Complications occur most often in very young children, adults, or people with damaged immune systems.