What are immunizations?

Immunizations save lives. They are the best way to help protect you or your child from certain infectious diseases. They also help reduce the spread of disease to others and prevent epidemics. Most are given as shots. They are sometimes called vaccines, or vaccinations.

In many cases when you get a vaccine, you get a tiny amount of a weakened or dead form of the organism that causes the disease. This amount is not enough to give you the actual disease. But it is enough to cause your immune system to make antibodies that can recognize and attack the organism if you are ever exposed to it.

Sometimes a vaccine does not completely prevent the disease, but it will make the disease much less serious if you do get it.

Some immunizations are needed only one time. Others require several doses over time to help your body be able to fight the disease (build immunity).

What are some reasons to get immunized?

• Immunizations protect you or your child from dangerous diseases.
• They help reduce the spread of disease to others.
• They are often needed for entrance into school or day care. And they may be needed for employment or for travel to another country.
• Getting immunized costs less than getting treated for the diseases that the shots protect you from.
• The risk of getting a disease is much greater than the risk of having a serious reaction to the vaccine.
• When immunization rates drop below a certain level, preventable diseases show up again. Often, these diseases are hard to treat. For example, measles outbreaks still occur in the U.S.

If you are a woman who is planning to get pregnant, talk to your doctor about what immunizations you have had and what you may need to protect your baby. And if you live with a pregnant woman, make sure your vaccines are up-to-date.

Traveling to other countries may be another reason to get immunized. Talk with your doctor months before you leave, to see if you need any shots.

What immunizations are recommended for children and adolescents?

Ask your doctor what shots your child should get. The immunization schedule includes vaccines for:

• Bacterial meningitis.
• Chickenpox.
• Diphtheria, tetanus, and pertussis (also known as whooping cough).
• Flu (influenza).
• Haemophilus influenzae type b disease, or Hib disease.
• Hepatitis A.
• Hepatitis B.
• Human papillomavirus (HPV).
• Measles, mumps, and rubella.
• Pneumococcal disease.
• Polio.
• Rotavirus.

Immunizations start right after birth, and many are given throughout a baby's first 23 months. Booster shots (the later doses of any vaccines that need to be repeated over time) occur throughout life.

Fewer immunizations are needed after age 6. But older children and teens need shots too (such as those for bacterial meningitis and for tetanus, diphtheria, and whooping cough). Some shots are also given during adulthood (such as a tetanus shot).

It is important to keep a good record, including a list of any reactions to the vaccines. When you enroll your child in day care or school, you may need to show proof of immunizations. Your child may also need the record later in life for college, employment, or travel.

Talk to your doctor if you or your child plans to be in a group living situation, like a college dormitory or summer camp. You may want certain shots, like those for meningitis.

What vaccines are recommended for adults?

The vaccines you need as an adult depend not only on your age, lifestyle, overall health, pregnancy status, and travel plans but also on who you are in close contact with and what vaccines you had as a child.

Talk to your doctor about which vaccines you need. Common adult vaccines include:

• Flu.
• Human papillomavirus (HPV).
• Pneumococcal.
• Shingles.
• Tetanus, diphtheria, and pertussis.

In some states, pharmacists can give some of these shots.

What are the side effects of vaccines?

Most side effects from vaccines are minor, if they occur at all. Ask your doctor or pharmacist about the reactions that could occur. They may include:

• Redness, mild swelling, or soreness where the shot was given.
• A slight fever.
• Drowsiness, crankiness, and poor appetite.
• A mild rash 7 to 14 days after chickenpox or measles-mumps-rubella shots.
• Temporary joint pain after a measles-mumps-rubella shot.

Serious reactions, such as trouble breathing or a high fever are rare. If you or your child has an unusual reaction, call your doctor.

How safe are vaccines?

False claims in the news have made some parents concerned about a link between autism and the shot for measles, mumps, and rubella. But studies have found no link between vaccines and autism.^{1, 2}

Some parents question whether mercury-containing thimerosal (used as a preservative in vaccines) might cause autism. Studies have not found a link between thimerosal-containing vaccines and autism.³ Today, all routine childhood vaccines made for the U.S. contain either no thimerosal or only trace amounts.⁴

Two major government agencies, along with vaccine makers and other groups, watch for, study, and keep track of adverse events that occur after vaccines are given.