Childhood Immunization (Vaccination) Schedule

Why do we need vaccines?

None of us wants to see our children get sick. If we could, we would protect them from any illness, no matter how small, even the sniffles.

Now suppose you could make your child safe from some of the most deadly diseases in history. Suppose that at the same time you could also help protect your neighbors' children and other children around the country from the same diseases. Finally, you could actually help to rid the world of some of these diseases that have been crippling and killing children for centuries.

You can do all of these things with one of the easiest and yet most powerful health tools ever developed. You can make sure you immunize your children.

How do vaccines work?

When you receive a vaccine, it helps your body to create antibodies. Antibodies are the body's defenses that fight off any foreign substances (germs). Although your body can create antibodies on its own, many of the vaccine-preventable diseases cause severe illness and even death before your body can produce enough antibodies.

Immunization (vaccination) schedule

Vaccines work best when given at certain ages. For example, health care professionals do not usually administer the measles vaccine until a child is at least 1 year old. If a child receives the measles vaccine earlier than that, it may not work as well. On the other hand, the DTaP vaccine should be given over a period of time in a series of properly spaced doses. More information about the specific diseases your child is vaccinated against is listed later in this article.

Following is a description of the routine childhood immunization schedule. The U.S. Centers for Disease Control and Prevention (CDC) publishes the schedule each year.

What are the recommended childhood vaccines, and at what ages they should be given?

Hepatitis B vaccine:

  1. First dose at birth before discharge from the hospital
  2. Second dose at 1 to 2 months
  3. Third dose at 6 to 18 months

Hib vaccine:

  1. First dose at 2 months
  2. Second dose at 4 months
  3. Third dose at 6 months (depending upon type of Hib vaccine given)
  4. Fourth dose at 12 to 15 months

Inactivated polio vaccine (IPV):

  1. First dose at 2 months
  2. Second dose at 4 months
  3. Third dose at 6 to 18 months
  4. Fourth dose at 4 to 6 years

DTaP vaccine:

  1. First dose at 2 months
  2. Second dose at 4 months
  3. Third dose at 6 months
  4. Fourth dose at 15 to 18 months
  5. Fifth dose at 4 to 6 years
  6. Health care professionals recommend that children receive the Tdap at 11 years of age. In certain U.S. states (for example, California), entry into seventh grade requires receipt of the Tdap vaccination.

Pneumococcal vaccine:

  1. First dose at 2 months
  2. Second dose at 4 months
  3. Third dose at 6 months
  4. Fourth dose at 12 to 18 months

Rotavirus vaccine:

  1. First dose at 2 months
  2. Second dose at 4 months
  3. Third dose at 6 months (depending upon type of rotavirus vaccine given)

Hepatitis A vaccine:

  1. First dose at 12 to 23 months
  2. Second dose at 6 to 18 months after the first dose

Influenza vaccine:

  1. First dose at 6 months (requires a booster one month after initial vaccine if less than 9 years of age)
  2. Annually after that

MMR (measles, mumps, and rubella) vaccine:

  1. First dose at 12 to 15 months
  2. Second dose at 4 to 6 years

Varicella (chickenpox) vaccine:

  1. First dose at 12 to 15 months
  2. Second dose at 4 to 6 years

Meningococcal vaccine (Men ACWY):

  1. First dose at 11 years
  2. Second dose at 16 years

Meningococcal B vaccine:

  1. First dose at 16-18 years
  2. Second dose six months after the first dose

Human papillomavirus vaccine (two schedules):

If first dose given before 15 years:

  1. First dose at 11 years
  2. Second dose six months after first dose

If first does given after 15 years:

  1. Second dose two months after first dose
  2. Third dose six months after first dose


Childhood Diseases: Measles, Mumps, & More See Slideshow

What should you do if your child misses a shot?

For most vaccines, it is never too late to catch up on missed shots. Children who missed their first shots at 2 months of age can start later. Children who have received some of their shots and then fallen behind schedule can catch up without having to start over. If you have children who were not immunized when they were infants, or who have gotten behind schedule, contact your doctor or the health department clinic. They will help you get your children up to date on their immunizations.

(NOTE: Don't postpone your child's immunizations just because you know he or she can catch up later. Every month a child goes without scheduled immunizations is a month that the child is unprotected from vaccine-preventable diseases.)

Combination vaccines

A combination vaccine is more than one vaccine contained in a single shot. Doctors and parents both like them because they allow a child to get several vaccines at once without having to get as many injections. Several combination vaccines are already in use (for example, MMR, MMRV, DTaP, Hib/HepB, DTaP/IPV/HepB, DtaP/IPV/Hib, and DtaP/IPV). More are under development.

Vaccination checklist

Rarely, a child should wait before getting certain vaccines or should not get them at all. Tell your doctor or nurse if any of these apply to your child on a day when an immunization visit is scheduled.

  1. Is your child very sick today? (He or she has more than a common cold, earache, etc.)
  2. Does your child have any severe (life-threatening) allergies?
  3. Has your child ever had a severe reaction after a vaccination?
  4. Does your child have a weakened immune system (because of diseases such as cancer or medications such as steroids)?
  5. Has your child received a transfusion or any other blood product recently?
  6. Has your child ever had convulsions or any kind of nervous system problem?
  7. Will your child be exposed to anyone with a compromised immune system (for example, receiving cancer chemotherapy)?

What are the vaccine-preventable diseases?

Hib vaccine

  • This vaccine protects against infection with the Haemophilus influenzae type b bacteria.
  • These bacteria cause meningitis (an inflammation of the covering membranes that surround the brain) and may cause brain damage. Also these bacteria can infect the blood, joints, bones, muscles, throat, and the cover surrounding the heart. This is especially dangerous for babies. Before the vaccine era, this was an extremely common cause of acquired brain injury in children and infants. The Hib vaccine does not protect against the influenza virus and does not protect against the flu.

DTaP vaccine

The D in DTaP stands for diphtheria.

  • Corynebacterium diphtheriae is a bacterium that attacks the throat, mouth, and nose. This is a very contagious disease (easy to get), but occurrences have been rare since the vaccine was created.
  • Diphtheria can form a gray web that may completely cover the windpipe and cause someone to stop breathing.
  • Also, if this disease is not treated right away, it could cause pneumonia, heart failure, or paralysis.

The T in DTaP stands for tetanus.

  • Tetanus is an infection caused by a type of bacteria found in dirt, gravel, and rusty metal. It usually enters the body through a cut.
  • Infection with tetanus bacteria causes the muscles to spasm (move suddenly). If tetanus attacks the jaw muscles, it causes lockjaw, which is the inability to open and close your mouth.
  • Tetanus can also cause the breathing muscles to spasm, with potentially fatal consequences.

The P in DTaP stands for pertussis.

  • Bordetella pertussis is the type of bacteria that causes whooping cough. It infects the airways and destroys the cells responsible for clearing mucus and other debris. This results in an infection associated with a severe prolonged cough and typical "whoop." The cough can last for more than two months and typically causes severe illness in the very young and very old. Recently recommendations were added to administer boosters to adolescents. Infants who develop pertussis are at moderate risk for the development of seizures.

Polio vaccine

  • A virus causes polio. It can cause paralysis of the legs and chest, making walking and breathing difficult or impossible.
  • The first symptoms of polio are fever, sore throat, headache, and a stiff neck. Polio is very rare in the United States since the vaccine became available; however, it is still somewhat common in other countries.

MMR vaccine

The first M in MMR stands for measles.

  • Measles is a highly contagious (easy to get) virus that causes a high fever, cough, and a spotty rash all over the body. It may also cause ear infections and pneumonia.

The second M in MMR stands for mumps.

  • Mumps is a virus which causes painful, swollen salivary glands, which are located in front of the ears (where sideburns are located), as well as a fever and a headache.
  • Mumps also may cause serious problems, including meningitis or hearing loss. It can cause inflammation of the testicles (orchitis) in males.

The R in MMR stands for rubella.

Hepatitis B vaccine

  • Hepatitis B is a virus that causes inflammation of the liver. Signs and symptoms are extreme tiredness and jaundice (moderate yellowing of the whites of the eyes and skin). It may cause the liver to stop working and has been associated with lifelong infection, liver failure, liver cancer, and even death.

Varicella vaccine

  • Varicella is the virus that causes chickenpox. It causes an itchy rash and a fever. You can catch it from someone who already has it if you touch an open blister on that person's skin or if that person sneezes or coughs around you. Varicella infection, though usually believed to be mild, also causes pneumonia (lung infections) and encephalitis (brain infections).

Pneumococcal vaccine

Hepatitis A vaccine

  • Hepatitis A is a virus similar to hepatitis B. Transmission occurs by coming in contact with contaminated food or drink. Contamination of foods may occur from food handlers not following proper hygiene procedures. Early symptoms of the disease are nonspecific and may include fever, diarrhea, and abdominal pain. It causes acute liver disease. It can affect anyone at any age, and in the United States, it can occur as isolated cases or even in epidemics.

Meningococcal vaccine

  • Neisseria meningitidis is a bacterium that causes meningitis (brain infection), sepsis (blood infection), and other infections. It is very dangerous infection and can cause seizures and death. Often outbreaks occur in epidemics.

Rotavirus vaccine

  • Rotavirus is a virus that causes severe diarrhea in very young infants. It causes over 55,000 hospitalizations each year in the United States and over 400,000 deaths worldwide. Children with this virus develop vomiting and watery diarrhea, which causes them to become dehydrated.

Human papillomavirus vaccine

Influenza vaccine

  • Influenza is a virus that causes severe respiratory illness. There are two major types, influenza A and influenza B. Each year, a new influenza vaccine is required because of the virus' tendency to mutate (change). The flu, as the disease is called, causes the most severe illness in the very young and the very old.

For more information about vaccinations, please visit the MedicineNet Immunizations (Vaccinations) Center and

The Food and Drug Administration ( and the Centers for Disease Control and Prevention ( kindly provided portions of the above information.

Medically reviewed by Heather Schultz, MD; Board Certified Pediatrics


United States. Centers for Disease Control and Prevention. "Immunization Schedules." Feb. 6, 2018. <>.

United States. Centers for Disease Control and Prevention. "Recommended Immunization Schedule for Persons Aged 0 Through 18 Years -- United States, 2014." <>.