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Quick Facts

Childhood Vaccinations


The Manual's Editorial Staff

Last full review/revision Sep 2019| Content last modified Sep 2019
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What are vaccinations (vaccines)?

Vaccines are a way of getting your body ready to fight off certain infections. They don't fight infections after you're sick, like medicines do. Instead, vaccines help you avoid getting sick from certain infections.

Vaccines are sometimes called "immunizations," because vaccines teach your immune system how to fight off certain diseases. If you have been protected against a disease by a vaccine, you are said to be "immune" to the disease.

Each vaccine works to prevent only one type of infection. For example, the flu vaccine only helps prevent the flu. And you may need to get a vaccine several times for it to be fully effective. Because vaccines are usually given by shot (injection), several vaccines are often combined into one shot so that you need fewer shots.

  • Doctors give babies and children vaccines based on a standard schedule

  • Doctors created the schedule based on the age children become at risk for different infections

  • Not following the schedule and getting shots late make it more likely your child will get a serious infection

Do vaccines work?

Yes, vaccines lower the risk that your child will get an infection. Children who don’t get vaccines are more likely to get sick or die from certain infections than children who get vaccines. However, no vaccine works 100% of the time. A few children who've gotten vaccines for certain infections still get sick from those infections.

In the past, thousands of children died every year because of diseases that are now preventable by vaccines. Hundreds of thousands became seriously ill. Because of vaccines:

  • One deadly disease, smallpox, has been completely eliminated

  • Other serious diseases such as polio, diphtheria, and tetanus now almost never happen in the United States

  • Some common diseases are much less frequent such as measles, whooping cough (pertussis), and mumps

If infections are rare, why should my child get vaccines?

Many infections that vaccines can prevent still happen in the United States and are still common in other parts of the world. They can spread very quickly among children who haven't gotten vaccines. For example, measles cases are increasing in the United States. This increase is probably the result of fewer children receiving the measles vaccine. This is why it's important for all children to get vaccines.

What diseases can be prevented by vaccines?

Vaccines are available for the infections listed below that can affect children. Many are very contagious, which means they can spread easily and quickly to other people. That means that when your child receives a vaccine it helps protect other people too.

  • Chickenpox

  • Diphtheria

  • Haemophilus influenzae type b (which can cause meningitis and pneumonia)

  • Hepatitis A

  • Hepatitis B

  • Human papillomavirus (which can cause cancer of the cervix in girls and genital warts in girls and boys)

  • Influenza (the "flu")

  • Measles

  • Meningococcal infection (which can cause meningitis)

  • Mumps

  • Pertussis (whooping cough)

  • Pneumococcal infections (which can cause ear infections, sinus infections, pneumonia, and meningitis)

  • Polio

  • Rotavirus

  • Rubella (German measles)

  • Tetanus

Are vaccines safe?

Yes, vaccines are considered to be very safe. A few children develop side effects, but the side effects are rarely serious. And the diseases vaccines prevent are more dangerous to your child than the side effects of the vaccines.

  • Before a vaccine can be used, it’s tested for safety

  • Often, the side effects are minor, such as pain where the shot was given, a rash, or a mild fever

  • Very rarely, vaccine side effects are more serious, such as a fever so high it causes a seizure

  • If your child has any problems after getting a vaccine, tell your child’s doctor right away

Will vaccines give my child autism?

No, there is no known link between vaccines and autism.

  • Doctors from across the world have done many studies to look for a connection between vaccines and autism and didn’t find one

  • Children who get vaccines are no more likely to get autism than are children who don’t get vaccines

NOTE: This is the Consumer Version. DOCTORS: Click here for the Professional Version
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