Immunizations for children: What you need to know

Immunizations are designed to protect against serious illnesses ranging from polio and tetanus to measles, mumps, and the seasonal flu. Many people consider them the most important part of well-child checkups.

To find out more about the many illnesses prevented by immunizations, click on the links below under "recommended immunization schedule."

For a personalized list and schedule of immunizations recommended for your child, try our Immunization Scheduler.

How immunizations work

Immunizations are vaccines made of either weakened or "killed" versions of the bacteria or virus that causes a particular disease. When these altered viruses and bacteria are injected or taken orally, the immune system mounts an attack that stimulates the body to produce antibodies.

Once produced, the antibodies remain active in the body, ready to fight off the real disease. For example, if whooping cough broke out in your area, an immunized child would be much less likely to contract the disease than one who wasn't immunized.

2015 immunization schedule

Every year, the U.S. Centers for Disease Control's Advisory Committee on Immunization Practices publishes a new schedule showing which vaccines are recommended and when to get them. This schedule is endorsed by the American Academy of Pediatrics and the American Academy of Family Physicians.

If your child is behind on immunizations, ask your doctor about the "catch-up" schedule.

DTaP, to protect against diphtheria, tetanus, and pertussis (whooping cough):

• At 2 months
• At 4 months
• At 6 months
• Between 15 and 18 months (can be given as early as 12 months as long as it's at least six months after the previous shot)
• Between 4 and 6 years old
• A booster shot at 11 or 12 years of age (called the Tdap)

Hepatitis A, to protect against hepatitis A, which can cause the liver disease hepatitis:

• Between 12 and 23 months, two shots, six to 18 months apart

Hepatitis B, to protect against hepatitis B, which can cause the liver disease hepatitis:

• At birth
• Between 1 and 2 months
• Between 6 and 18 months

Hib, to protect against Haemophilus influenza type B, which can lead to meningitis, pneumonia, and epiglottitis:

• At 2 months
• At 4 months
• At 6 months (not needed if the PedvaxHIB or Comvax brand of vaccine was given at 2 and 4 months)
• Between 12 and 15 months

HPV, to protect against human papillomavirus, the most common sexually transmitted disease in the United States and a cause of genital warts and of cervical, anal, and throat cancers:

• Three doses for girls and boys at age 11 or 12 years

Influenza (the flu shot or, for age 2 and up, nasal spray vaccine), to protect against seasonal flu and H1N1 (swine flu):

• Age 6 months and up, every year in the fall or early winter
• One dose for most children
• Two doses for children 6 months to 8 years old who are getting the flu vaccine for the first time or who haven't had two doses since July 2010

Meningococcal, to protect against meningococcal disease, the leading cause of bacterial meningitis in U.S. children in pre-vaccine days:

• Between 11 and 12 years
• A booster shot at 16 years of age

MMR, to protect against measles, mumps, and rubella (German measles):

• Between 12 and 15 months
• Between 4 and 6 years old

Pneumococcal (PCV), to protect against pneumococcal disease, which can lead to meningitis, pneumonia, and ear infections:

• At 2 months
• At 4 months
• At 6 months
• Between 12 and 15 months

Polio (IPV), to protect against polio:

• At 2 months
• At 4 months
• Between 6 and 18 months
• Between 4 and 6 years old

Rotavirus, (given orally, not as an injection) to protect against rotavirus, which can cause severe diarrhea, vomiting, fever, and dehydration:

• At 2 months
• At 4 months
• At 6 months (not needed if the Rotarix brand of vaccine was given at 2 and 4 months)

Varicella, to protect against chicken pox:

• Between 12 and 15 months
• Between 4 and 6 years.