Vaccine Basics

Vaccines help prevent people from getting sick. They also help reduce the spread of disease to others and prevent epidemics. There are many kinds of vaccines. Each vaccine is made up of parts of weakened or killed bacteria or viruses of a specific disease. After you have a vaccine, your body's immune system makes antibodies to fight the disease. If you are exposed to the same disease in the future, the antibodies kill the bacteria or viruses before they have a chance to make you sick.

If you get a vaccine, it may not completely prevent you from getting a disease, but it makes it much less likely. If you get a disease even after you have been vaccinated, it usually will be only a mild case.

Vaccines are usually given by shot (injection). Some are given by mouth as a pill or liquid, or by a spray (aerosol) into the nose. Vaccines are also called immunizations.

Immunization Schedules

In the United States, the Centers for Disease Control and Prevention (CDC) and other national organizations advise people about which immunizations they should get and when. Immunization schedules are for healthy children, teens, and adults as well as people with health problems and other circumstances, including pregnancy, asthma, or diabetes.

• To see a list of recommended shots based on your child's birth date, go to the CDC interactive Web site at www2a.cdc.gov/nip/kidstuff/newscheduler_le.
• To see what shots you or your teen may need, go to the CDC interactive Web site at www2.cdc.gov/nip/adultImmSched.

Children and teens in the United States usually need proof that all their immunizations are up-to-date before they can start school or day care. Also, students of any age entering college usually need to have a written record showing that their immunizations are up-to-date.

For more information on when to get vaccines, see the topic Immunizations.

The CDC may recommend certain immunizations for people who are going to travel to a foreign country. For more information, see the topic Travel Health.

Vaccine Information Statements

The Centers for Disease Control and Prevention (CDC) creates Vaccine Information Statements (VISs), which have details about most vaccines given in the United States. The VISs are updated when needed.

The information in these statements does not change often. Each VIS explains why to get the vaccine, the risks from the vaccine, what to do if you or your child has a moderate or severe reaction, and more.

If you have any questions about a vaccine, see the CDC Web site www.cdc.gov/vaccines, or talk to your doctor.

There are Vaccine Information Statements for:

• Anthrax (What is a PDF document?)
• Chickenpox (Varicella) (What is a PDF document?)
• Diphtheria/Tetanus/Pertussis (DTaP) (What is a PDF document?)
• H1N1 flu (influenza) nasal spray (What is a PDF document?)
• H1N1 flu shot (What is a PDF document?)
• Haemophilus Influenzae Type b (Hib) (What is a PDF document?)
• Hepatitis A (What is a PDF document?)
• Hepatitis B (What is a PDF document?)
• Human Papillomavirus (HPV) (What is a PDF document?)
• Japanese Encephalitis (What is a PDF document?)
• Measles/Mumps/Rubella (MMR) (What is a PDF document?)
• Meningococcal (What is a PDF document?)
• Pneumococcal Conjugate (PCV) (What is a PDF document?)
• Pneumococcal Polysaccharide (PPSV) (What is a PDF document?)
• Polio (IPV) (What is a PDF document?)
• Rabies (What is a PDF document?)
• Rotavirus (What is a PDF document?)
• Seasonal flu (influenza) nasal spray (What is a PDF document?)
• Seasonal flu shot (What is a PDF document?)
• Shingles (What is a PDF document?)
• Smallpox (Vaccinia) (What is a PDF document?)
• Tetanus/Diphtheria (Td) and Tetanus/Diphtheria/Pertussis (Tdap) (What is a PDF document?)
• Typhoid (What is a PDF document?)
• Yellow Fever (What is a PDF document?)

Other Places To Get Help

Organization

Related Information

• Immunizations

References

Other Works Consulted

• Centers for Disease Control and Prevention (2010). Recommended immunization schedules for persons aged 0 through 18 years—United States, 2010. MMWR, 58(51 and 52): 1–4. Also available online: http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5851a6.htm?s_cid=mm5851a6_e.
• Centers for Disease Control and Prevention (2010). Recommended adult immunization schedule—United States, 2010. MMWR, 59(01): 1–4. Also available online: http://www.cdc.gov/mmwr/PDF/wk/mm5901-Immunization.pdf.

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