The infant immunization schedule is never set in stone. With new info, new vaccines, and improved vaccinations, over the years doctors have adjusted the vaccine schedule making it even safer and more effective for little ones. For example, back in 1963 babies got the measles vaccine at 9 months old, but in 1965 it was bumped to 12 months. Then, in the mid-70s, the timing moved to 15 months because evolving research showed that the vaccine was more effective when administered at that age.

To keep the recommended vaccine schedule up to date, the Centers for Disease Control and Prevention (CDC) enlists the help of vaccine experts, scientists, doctors, and public health professionals to review available data not only on new vaccines, but existing ones, too. The group—known as the Advisory Committee on Immunization Practices (ACIP)—meets three times a year to discuss vaccine recommendations and, in the end, they publish their official stance for vaccinating children and adults in America. The CDC then sets the immunization schedules based on ACIP’s recommendations. (The childhood and adolescent immunization schedules are also approved by the American Academy of Pediatrics, the American Academy of Family Physicians, and the American College of Obstetricians and Gynecologists.)

Vaccination Schedule for Babies and Kids

As of 2022, this is the current recommended vaccine schedule for children and adolescents:

  • Birth: HepB*

  • Between 1 and 2 months: HepB

  • 2 months: RV, DTap, Hib, PCV13, IPV

  • 4 months: RV**, DTap, Hib, PCV13, IPV

  • Between 6 and 18 months: HepB, IPV

  • 6 months: DTap, Hib***, PCV13, Flu shot (annual, second dose 4 weeks later for first timers)

  • Between 12 and 15 months: Hib, PCV13, MMR, VAR

  • Between 12 and 23 months, HepA (second dose ~6 months later)

  • Between 15 and 18 months: DTap

  • Between 2 and 6 years: Flu shot (annual, nasal spray flu vax now an option; second dose 4 weeks later for first timers)

  • Between 4 and 6 years: DTap, IPV, MMR, VAR

  • 9+ years: HPV (can start at 9 if desired or wait until 11 to 12), Tdap (11 to 12 years), MenACWY (11 to 12 years and 16)

* If you tested negative for HepB in the hospital, your pediatrician may recommend waiting to get your baby’s HepB shot until their first doctor visit.

** There’s a third RV dose at 6 months for those who got RotaTeq (RV5)

*** Those who received PedvaxHIB don’t require a 6-month shot

At first glance, this vaccine schedule looks kind of like alphabet soup! But all these head-scratching letter combos stand for super-important shots babies and kids need to stay protected from various infections and diseases. Let’s break down what each one means….

Hepatitis B Vaccine (HepB)

This vaccine protects against hepatitis B, which is a serious liver disease that can lead to liver failure and cancer. There is no cure for hepatitis B, but fortunately the HepB vaccine offers 98% to 100% protection against the disease. (Learn about Dr. Harvey Karp’s take on the HepB vaccine.)

When Babies Get the HepB Vaccine

It’s often recommended that babies get the first of the three-dose vaccine within 12 to 24 hours of birth. A second dose is recommended between 1 and 2 months, with the last dose coming in between 6 and 18 months. There can be slight variations on the timing of Baby’s first dose depending on their weight and/or the birthing parent’s hepatitis B status. Some providers might suggest waiting until your little one’s first doctor’s visit before they get their first shot. (This is a great question to ask when interviewing pediatricians!)

HebB Vaccine Schedule:

  • First Dose: At birth (with exceptions)
  • Second Dose: Between 1 and 2 months
  • Thir­d Dose: Between 6 and 18 months

HepB Vaccine Side Effects  

No serious reactions been linked to this vaccine. Instead, your bub may experience a low fever (less than 101 degrees Fahrenheit) and/or a sore injection site.

Rotavirus Vaccine (RV)

Rotavirus is the most common cause of severe diarrhea and vomiting in infants and young children, which can lead to dangerous dehydration. Pre-vaccine, rotavirus sent more than 200,000 children to the emergency room and caused up to 60 deaths annually in little ones under 5 years old. Now, according to the CDC, about 90% of babies who get rotavirus vaccine are protected from severe rotavirus disease and roughly 70% are protected from contracting rotavirus disease entirely.

When Babies Get the Rotovirus Vaccine

Babies should get their first dose of the rotavirus vaccine—which is not a shot but drops administered orally—at their 2-month checkup. If your baby gets the RotaTeq (RV5) vaccine, they’ll get follow-up doses at 4 months and 6 months. But if your baby received the Rotarix (RV1) vaccine, there’s no third dose at 6 months. No matter which, the first dose of the rotavirus vaccine must be administered before your baby is 15 weeks old and the last dose must be given by 8 months. (If any dose in the series is unknown, doctors will default to the three-dose course.)

Rotavirus Vaccine Schedule:

  • First Dose: 2 months
  • Second Dose: 4 months
  • Third Dose: 6 months (only if given RV1 vaccine)

Rotavirus Vaccine Side Effects

Most little ones who get the rotavirus vaccine don’t experience any side effects. However, some become slightly irritable, or have mild, temporary diarrhea, or vomiting, that go away on their own. Serious side effects are rare.

Diphtheria, Tetanus, and Acellular Pertussis Vaccine (DTaP and Tdap)

The DTaP vaccine helps protect your baby from three infections: diphtheria, tetanus, and pertussis (aka whooping cough). Highly contagious diphtheria was once the leading cause of childhood death around the world. It brings about serious breathing and swallowing issues, plus painful skin sores. Meanwhile, tetanus affects the nervous system, causing painful tightening in jaw and neck muscles, making it difficult to breathe and swallow. And the super-contagious whooping cough is a respiratory disease marked by uncontrollable and violent coughing, making it difficult to breathe. Whooping cough is very dangerous (even deadly) for babies less than a year old.

The good news? The DTaP vaccine is up to 90% effective against whooping cough, virtually 100% effectiveness against tetanus, and 97% effective against diphtheria in children who receive all recommended doses on schedule.

When Babies Get the DtaP Vaccine

Your baby should receive their DtaP vaccines at 2 months, 4 months, and 6 months. The fourth dose will be administered between 15 and 18 months and the fifth comes between 4 and 6 years old. After that, the DTaP is traded in for the Tdap, which is virtually the same vaccine with an altered makeup for kids 7 and up and adults. Adolescents should get a single dose of the Tdap vaccine between age 11 and 12 years old.

DTaP Vaccine Schedule:

  • First Dose: 2 months
  • Second Dose: 4 months
  • Third Dose: 6 months
  • Fourth Dose: Between 15 and 18 months
  • Fifth Dose: Between 4 and 6 years
  • Sixth Dose: Between 11 and 12 years with the Tdap vaccine

Adults should receive a Tdap booster every 10 years. (Boosters can be either Tdap or Td, a vaccine that protects against tetanus and diphtheria, but not whooping cough.) Pregnant individuals need be vaccinated between 27 and 36 weeks of each pregnancy to protect the newborn from whooping cough.

DTaP Vaccine Side Effects

Possible side effects may include tenderness, swelling, redness, fever and/or loss of appetite within a couple of days post-shot.

Haemophilus Influenzae Type B Conjugate Vaccine (HiB)

Never heard of HiB? That’s because the vaccine works! Before the vaccine, HiB was the leading cause of meningitis in children under 5 years old, but with the vaccine more than 95% of babies develop protective antibody levels against HiB after receiving all doses. Beyond meningitis, the HiB vaccine protects children from other dangerous infections of the lungs, blood, skin, and joints.

When Babies Get the HiB Vaccine

HiB is another multi-vaccine regimen, including shots at 2 months, 4 months, and 6 months, with a final vaccine dose administered between 12 and 15 months. This schedule is not the same for all, however. If your child received the three-dose PedvaxHIB vaccine, then their line-up looks like this: 2 months, 4 months, booster between 12 and 15 months.

HiB Vaccine Schedule:

  • First Dose: 2 months
  • Second Dose: 4 months
  • Third Dose: 6 months (Child who received the PedvaxHIB vaccine don’t get the 6-month shot)
  • Fourth Dose: Between 12 and 15 months

HiB Vaccine Side Effects

Redness, warmth, and swelling at the shot site and fever are possible side effects. Sometimes dizziness and fainting can occur.

Pneumococcal Conjugate Vaccine (PCV13)

The PCV13 vaccine protects against disease caused by pneumococcal bacteria, including pneumonia, meningitis, and ear, sinus, and blood infections. While anyone can potentially get pneumococcal disease, children under 2 years old are among those at the highest risk of infection, which can potentially lead to brain damage, hearing loss, even death.

When Babies Get the Pneumococcal Vaccine  

This schedule should start to sound familiar: Babies receive the PCV13 vaccine at 2 months, 4 months, 6 months, and again between 12 and 15 months. Research shows that the PCV13 vaccine yields up to a 96% effectiveness against pneumococcal infections. But it’s important to know that young children may be at increased risk for seizures caused by fever if their PCV13 is given at the same time as the flu shot, so please speak to your pediatrician about the best schedule for the flu shot.

Pneumococcal Vaccine Schedule:

  • First Dose: 2 months
  • Second Dose: 4 months
  • Third Dose: 6 months
  • Fourth Dose: Between 12 and 15 months

PCV13 Vaccine Side Effects

Some possible side effects include redness, pain, swelling, and/or tenderness at the shot site. Fever, loss of appetite, feeling fussy or tired, headache, muscle aches, joint pain, and/or chills can also occur.

Inactivated Poliovirus Vaccine (IPV)

The poliovirus is behind polio, a life-threatening disease that can invade the spinal cord and possibly cause paralysis or paresthesia, which is the feeling of pins and needles in your legs. Poliovirus can also lead to meningitis. According to the CDC, 99% of children who receive all the recommended doses of polio vaccine are fully protected. But not too long ago—before the vaccine was introduced in 1955—polio was very common, paralyzing and killing thousands of people every year in the United States. Just recently, the first case of polio in decades has been diagnosed in America. The person was unvaccinated.

When Babies Get the Polio Vaccine

Babies get four doses of polio vaccine at the following intervals: 2 months, 4 months, between 6 and 18 months, and again between 4 and 6 years old. (While the oral vaccine is used in other countries, here IPV is given by shot in the leg or arm, depending on Baby’s age.)

Polio Vaccine Schedule:

  • First Dose: 2 months
  • Second Dose: 4 months
  • Third Dose: Between 6 and 18 months
  • Fourth Dose: Between 4 and 6 years old

One caveat: If your child is traveling to a country where the risk of getting polio is greater, such as Israel, Egypt, or Pakistan, and their polio series is not yet complete, talk to your pediatrician about an accelerated schedule.

Polio Vaccine Side Effects

The polio vaccine has not been shown to cause serious problems. The most common side effect is a sore spot where the vaccine was given.

Flu Vaccine

The influenza vaccine reduces the risk that your child will catch the flu, which is a virus that infects the nose, upper airways, throat, and lungs. The flu spreads lightning fast and can cause serious illness, especially for young children. While those who get the flu shot may still contract the flu, their illness is far less severe, which tamps down on serious flu complications and flu-related hospitalizations. Plus, it helps prevent spreading flu to babies younger than 6 months who are too young to get vaccinated. (Learn more about why the flu shot is so important for babies.)

When Babies Get the Flu Vaccine

Once the vaccine is available for the season, children can begin getting their annual flu shot at 6 months old. Some children will need two shots to be fully protected. (PS: It takes roughly two weeks post-shot to build immunity.) Flu vaccine effectiveness varies from year to year, depending on the strain of the virus that’s circulating. But generally speaking, flu vaccine effectiveness hovers between 40 and 60% in the U.S.

Flu Vaccine Schedule:

  • First Dose: Most children will only need one dose, including kids older than 9 and kids who are younger than 9 but have previously received at least two doses of the flu vaccine (for example, if your 2-year-old got a two-dose flu shot last year, they only need one dose going forward).
  • Second Dose: Children younger than 9 who are getting the flu vaccine for the first time need two shots at least one month apart.

Remember, the influenza viruses change yearly, so all children 6 months and older need a flu shot every year. Also, once your child is 2 years old, the nasal spray vaccine might be an option.

Flu Vaccine Side Effects

Side effects from the flu shot may include soreness, redness, or swelling at the shot site, headache, fever, nausea, and/or muscle aches. If your bub got the flu mist, mild side effects may include a runny nose and/or wheezing.

Measles, Mumps, and Rubella Vaccine (MMR)

The MMR vaccine offers three-way protection against measles, mumps, and rubella—all serious viral infections. Measles, known for its rash and fever, is especially dangerous in children younger than 5 years old, possibly leading to pneumonia, seizures, and/or brain swelling, which could lead to brain damage. At the same time, mumps can progress and result in serious problems like deafness and brain swelling. While rubella (aka German measles) is generally mild (fever, sore throat, rash, headache, and eye irritation) in children, it can cause arthritis in up to half of teenage and adult women. Plus, rubella in pregnancy can cause miscarriage or serious birth defects. (Learn more about the rise in measles cases.)

When Babies Get the MMR Vaccine

All children get two doses of MMR vaccine, starting between 12 and 15 months. The second dose should then be administered between the ages of 4 and 6 years old. For children who are between 12 months old and 12 years old, their pediatrician may offer the MMRV vaccine instead of the MMR. That extra letter—V—is for varicella, aka chickenpox. More than 95% of children who get the MMR vaccine will be protected from all the three diseases throughout their lives.

MMR Vaccine Schedule:

  • First Dose: Between 12 and 15 months
  • Second Dose: Between 4 and 6 years old

If your child will be traveling outside the United States, they can get their MMR vaccine as early as 6 months old. They’ll still need to get doses between 12 and 15 months and between 4 and 6 years, though.

MMR Vaccine Side Effects

Mild to moderate side effects, like a sore arm, fever, mild rash, mild joint pain, have been known to occur.

Varicella Vaccine (VAR)

Before the VAR vaccine came out 1995, chickenpox was one of the most common diseases of childhood, affecting almost all children before the age of 9. The varicella vaccine protects against this highly contagious disease, known for its super-itchy, blister-like rash. Two doses of the vaccine have shown to be 98% effective at preventing all chickenpox cases and 100% effective against severe chickenpox. This is important because chickenpox can lead to pneumonia, inflammation of the blood vessels, swelling of the brain, and/or infections of the skin, bloodstream, bones, or joints…and shingles, a painful rash, years later.

When Babies Get the Varicella Vaccine

It’s recommended that children get their first dose of the chickenpox vaccine between 12 and 15 months, followed by a second dose between the ages of 4 and 6 years old. Kids between 1 and 12 years might get their chickenpox vaccine by way of the MMRV vaccine, which is a combo of measles, mumps, rubella, and varicella. 

Chickenpox Vaccine Schedule:

  • First Dose: Between 12 and 15 months
  • Second Dose: Between 4 and 6 years old

It’s important to note that CDC recommends those 19 years old and older who have weakened immune systems should get two doses of the related shingles vaccine. And adults 50+ need two doses, too.

    Chickenpox Vaccine Side Effects

    Soreness or swelling at the shot site, plus mild fever and/or rash can occur. Serious reactions occur very rarely but may include pneumonia or seizures.

    Hepatitis A Vaccine (HepA)

    The HepA vaccine protects against hepatitis A, which causes liver infection, and research shows that the two-dose shot causes virtually 100% immunity! While children under 6 years old with hepatitis A usually don’t have symptoms, they can easily pass the disease to others, making them seriously ill.

    When Babies Get the HepA Vaccine

    It’s recommended that children get the HepA vaccine between 12 and 23 months, followed by a second dose at least 6 months after.

    HepA Vaccine Schedule:

    • First Dose: Between 12 and 23 months
    • Second Dose: At least 6 months after first dose

    HepA can be administered as early as 6 months if your little one will be traveling to a location where hepatitis A is common, such as China, Mexico, or the Caribbean. Your baby will still need their routine vaccination between 12 and 23 months (and the 6-month follow-up shot).

    HepA Vaccine Side Effects

    The hepatitis A vaccine is very safe—and very effective. Most of the side effects—which are mild—fade after a day or two. (Those include a sore arm from the shot, fatigue, fever, headache, and/or loss of appetite.)

    Human Papillomavirus (HPV) Vaccine

    The HPV vaccine prevents cancer caused by several types of HPV, such as cervical cancer, cancers of the mouth, throat, and penis. Plus, it prevents genital warts. While it’s true that most HPV infections go away on their own within two years, some last longer…and those are the infections that can cause cancer. Since the vaccine was first recommended in 2006, infections with HPV types that cause most HPV cancers—and genital warts—have dropped 88% among teen girls and 81% among young adult women!

    While some parents balk at vaccinating their child against an infection that’s spread through sexual contact, know that the HPV vaccine is more effective if given sooner. In fact, the AAP notes that preteens produce more antibodies after an HPV vaccination than older adolescents do.

    When Kids Get the HPV Vaccine

    The CDC recommends 11- to 12-year-olds get their two-dose HPV vaccine 6 to 12 months apart. However, the vaccine can be started at 9 years old. For kids 14 and under, two doses are the norm, but for those between 15 and 26 years, three doses of HPV vaccine are needed. 

    HPV Vaccine Schedule:

    • First Dose: Between 11 and 12 years old, but okay as young as 9
    • Second Dose: 6 to 12 months after initial dose
    • Third Dose: Only for ages 15 to 26 years old. If your child is over 15, their second dose should be two months after the initial shot…and the third dose needs to happen six months after their first dose.

    HPV Vaccine Side Effects

    Some people report having very mild side effects after their HPV shot, like a sore arm at the shot site, fever, dizziness, headache, fatigue, nausea, and/or muscle or joint pain.

    Meningococcal Conjugate Vaccine (MenACWY)

    This mouthful of a vaccine name protects against a bacterial infection that can cause meningitis, blood infections, kidney failure, hearing loss, and/or lifelong nervous system problems. If medical treatment is delayed, the infection can be fatal. In fact, according to the AAP, up to 20% of teens infected with meningococcal disease die. And about one in five who survive their infection have permanent disabilities. Symptoms include a flat rash, nausea, vomiting, sensitivity to light, confusion, and/or a stiff neck. While anyone can get meningococcal disease, those between 15 and 21 are most at risk. A testament to this vaccine’s effectiveness: The incidence of meningococcal disease in adolescents decreased by over 90% since the MenACWY vaccine was first recommended in 2005.

    When Kids Get the Meningitis Vaccine

    There are two types of meningococcal vaccines available that help protect against different strains of meningococcal disease. According to the CDC, all 11- to 12-year-olds should get a MenACWY vaccine, followed by a booster dose at 16.

    Meningitis Vaccine Schedule:

    • First Dose: Between 11 and 12 years old
    • Second Dose: 16 years old

    Teens between the ages of 16 and 18 may also receive a serogroup B meningococcal vaccine, dubbed MenB. Your child may get both types of vaccines at the same visit, but in different arms.

    MenACWY Vaccine Side Effects

    About 50% of the people who get a MenACWY vaccine experience mild side effects, like pain where the shot was administered, fatigue, muscle pain, and headache.

    COVID-19 Vaccine

    While the COVID-19 vaccine isn’t officially on the childhood immunization schedule, the Advisory Committee on Immunization Practices recommends the COVID-19 vaccine for everyone 6 months and older. They go on to note that the COVID-19 vaccine may be administered on the same day as other immunizations. For more details about the scheduling and dosing of the COVID-19 vaccine, refer to the CDC and our COVID vaccine explainer.

    Vaccine Schedule for Preemies

    Parents of premature babies may be concerned that their newborns are simply too fragile to adhere to the recommended childhood vaccination schedule. However, it’s not only perfectly safe for preemie to get their shots on time—it’s recommended. After all, if your preterm baby gets any of the infections that vaccines can prevent, their chance of suffering disease-related problems skyrockets. (A baby is considered premature when they’re born before 37 weeks of pregnancy.) The one exception: If your baby weighs less than 4 pounds, 6 ounces (2,000 grams), the AAP recommends waiting to vaccinate against hepatitis B until your little one’s 1-month checkup—or at the time of discharge—whichever comes first.​

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    Disclaimer: The information on our site is NOT medical advice for any specific person or condition. It is only meant as general information. If you have any medical questions and concerns about your child or yourself, please contact your health provider.