About Vaccinations for Infants and Toddlers (Birth through 3 years)

Overview

Vaccines help provide protection against many diseases. They help the body to increase protective antibodies that fight off infections. With antibodies, infants and toddlers may not develop illness from the infection or may not develop severe infection. There are many vaccines, also referred to as immunizations, that are given during infancy and childhood.

Each year, the U.S. Centers for Disease Control and Prevention (CDC) and its Advisory Committee on Immunization Practices (ACIP) reviews and provides updated guidance on vaccine-preventable diseases. The vaccine-preventable diseases that apply to infants and toddlers include:

  • COVID-19
  • Hemophilus Influenza Type B (HiB)
  • Hepatitis A
  • Hepatitis B
  • Influenza (Flu)
  • Measles, Mumps and Rubella
  • Meningococcus
  • Pneumococcus
  • Poliovirus
  • Respiratory Syncytial Virus (RSV)
  • Rotavirus
  • Tetanus, Diphtheria and Pertussis
  • Varicella (Chicken Pox)

Here’s a summary of each disease and recommended vaccines. These are general recommendations. The available vaccines listed those included in the June 2024 CDC update. New vaccines may become available, updated or recommended. Check with your healthcare professional regarding the specific vaccines that are available and timing of vaccination for your baby or toddler.

COVID-19 (Coronavirus Disease 2019)

  • COVID-19 is a disease caused by the SARS-CoV-2 virus. While infants and toddlers are less likely to become seriously ill from COVID-19, some children may develop severe COVID-19 and require hospitalization. Infants that were born prematurely or children with weakened immune systems may be at higher risk of developing severe illness with COVID-19.
  • The Centers for Disease Control and Prevention’s (CDC) Advisory Committee on Immunization Practices (ACIP) recommends that vaccination for COVID-19 be determined by individual decision-making. ACIP’s recommendation applies to all individuals six months and older.
  • Which COVID-19 Vaccines should infants and toddlers receive?
    • Moderna mRNA COVID-19 Vaccine (Spikevax) 6 months through 64 years of age with at least one underlying condition that puts them at high risk for severe outcomes from COVID-19
    • Pfizer mRNA COVID-19 Vaccine (Comirnaty) 5 years through 64 years of age with at least one underlying condition that put them at high risk for severe outcomes from COVID-19

Hemophilus Influenza Type B (HiB)

  • Hemophilus influenza disease is caused by a bacteria called Hemophilus influenza. It can cause many types of illnesses, including bronchitis (chest cold) in adults. It may cause serious infections including pneumonia (lung infection), meningitis (brain and spinal cord lining infection), epiglottitis (throat infection), cellulitis (skin infection), and arthritis (joint infection. The vaccine is available for a specific type of Hemophilus infection, called H. influenza, type B (HiB)
  • Who should receive the HiB vaccine? The HiB vaccine is usually given as a series of three to four shots during childhood at the following ages:
    • 2 and 4 months
    • 4 months
    • 6 months (depending on the vaccine used)
    • 12 to 15 months
  • What vaccines are available?
    • ActHIB, Hiberix, PedvaxHIB

Hepatitis A

  • Hepatitis A is a liver disease caused by infection with hepatitis A virus. It is highly contagious (easily spread) through person-to-person contact or eating contaminated food or drink. It can cause a variety of symptoms, including diarrhea, feeling tired, fever, joint pain, nausea and vomiting, and dark-colored urine or stool.
  • Who should receive hepatitis A vaccination? The CDC recommends that all children 12-23 months of age receive the hepatitis A vaccine.
  • What vaccines are available?
    • Havrix, Vaqta
    • There is also a combination hepatitis a and hepatitis b vaccine: Twinrix

Hepatitis B

  • Hepatitis B is a disease caused by the hepatitis B virus (HBV). HBV attacks the liver and may lead to cirrhosis (scarring of the liver), liver cancer, and liver failure. HBV is a lifelong infection. Although HBV is typically spread by sexual intercourse or injection drug use, it is still recommended for infants and toddlers to be vaccinated because the virus can be transmitted from a pregnant mother to her baby or if an infected person prechews food that they give to a child.
  • Who should receive the HBV vaccine? The HBV vaccine is usually given as a series of four shots during infancy at the following ages:
    • Birth
    • 1-2, 4 and 6 months
  • What vaccines are available?
    • Engerix-B, Heplisav-B, PreHevbrio, Recombivax HB
    • There is also a combination hepatitis A and hepatitis B vaccine: Twinrix

Influenza (Flu)

  • Influenza is a contagious respiratory illness caused by infection with influenza viruses, including influenza type a and influenza type B. These viruses cause the flu each year during “flu season”, generally October through May. The viruses may change each year, so new flu vaccines are created each year to be available starting around September.
  • Who should receive vaccine? All people 6 months old or older should receive the annual influenza vaccine each year, unless contraindicated (such as an allergic reaction to the flu shot).
  • What vaccines are available? There are many brands of flu shot available each year. Check with the doctor or pharmacist regarding whether a specific flu shot is recommended for your infant or toddler.

Measles, Mumps, and Rubella (MMR)

  • Measles, mumps and rubella are very contagious (easily spread) diseases caused by viruses. Each condition causes a variety of symptoms and may lead to serious complications.
  • As of September 19, 2025, the Advisory Committee on Immunization Practices (ACIP) recommends that toddlers through age three be immunized for varicella by standalone vaccination administered at the same time as the MMR vaccine, rather than the combination measles, mumps, rubella, and varicella (MMRV) vaccine.
  • The CDC Immunization Safety Office reports that healthy 12–23 months old toddlers have increased risk of febrile seizure seven to 10 days after MMRV vaccination compared to those given separate immunization for varicella and measles, mumps, and rubella (MMR). According to the CDC, the MMRV vaccine doubles the risk of febrile seizures without conferring additional protection from varicella compared to standalone vaccination.

Meningococcus

  • Meningococcal disease is relatively rare condition caused by the bacteria Neisseria meningitidis. Infection can cause meningitis and bloodstream infections that cause serious illness and could be deadly within hours. Meningococcal bacteria are spread through close or lengthy contact with infected people. Children younger than 1 year of age are at increased risk for infection due to their immature immune systems.
  • Who should receive the meningococcal vaccine? Meningococcus vaccines are usually given during the teen years. Vaccination may be recommended for infants and children 2 months of age and older who are at increased risk of infection due to immune system deficiencies.
    • What vaccines are available? Meningococcal conjugate vaccines (also called MenACWY) are approved for use in infants and young children. Other types of meningococcal vaccine (MenB and MenABCWY vaccines) are approved for use in older children and adults.

Pneumococcus

  • Pneumococcal disease is caused by infection with the bacterium Streptococcus pneumoniae. Pneumococcus can cause illnesses including pneumonia (lung infection), meningitis (brain and spinal cord lining infection), bacteremia (bloodstream infection), otitis media (middle ear infection), and sinusitis (sinus infection). Streptococcus pneumonia infection is spread through direct contact with respiratory secretions, like saliva and mucus.
  • Who should receive the pneumococcal vaccine (PCV)? The PCV is usually administered as a series of shots at the following ages:
    • 2, 4 and 6 months
    • 12-15 months
  • What vaccines are available?
    • Pneumococcal conjugate vaccine (PCV):
      • PCV 15 (Vaxneuvance): This vaccine is approved for use in people 2 months of age and older.
      • PCV20 (Prevnar 20): This vaccine is approved for use in people 2 months of age and older.
    • Pneumococcal polysaccharide vaccine (PPSV): Pneumovax 23. The PPSV23 vaccine is approved for use in adults 50 years old and older, and for people 2 years old and older who are at increased risk for pneumococcal disease.

Poliovirus

  • Poliovirus has been eliminated in most parts of the world because of widespread vaccination. The virus may cause symptoms such as sore throat, fever, fatigue, nausea or headache. In most cases the symptoms go away on their own after a few days. In rare cases the virus can cause an infection of the covering of the brain and spinal cord called meningitis, or paralysis of the arms and legs that can be permanent. In the worst cases, poliovirus can cause death. The virus is very contagious and can be spread by infected people even if they don’t know they are sick. The virus enters the body through the mouth, either by coming in contact with contaminated food, toys or other objects, close contact with an infected person or eating or drinking food that are contaminated with the feces (poop) of an infected person. The best way to protect against infection by the poliovirus is vaccination.
  • Who should receive the inactivated polio vaccine (IPV)? The IPV is usually administered as a series of four shots at the following ages:
    • 2 and 4 months
    • 6-18 months
    • 4-6 years
  • What vaccines are available?
    • Inactivated polio vaccine (IPV): This is the only vaccine available in the United States.
    • Combination vaccines (Infanrix, Pentacel, Pediarix, VAXELIS): Several manufacturers supply different combinations of polio, diphtheria, tetanus, pertussis, Hemophilus influenza B and Hepatitis B vaccines that are approved for infants and toddlers.

Respiratory Syncytial Virus (RSV)

  • Infection with RSV, a common respiratory virus, often causes mild, cold-like symptoms. Infants are more likely to develop severe RSV illness and require hospitalization. RSV infections often occur during the fall and winter months, or “flu season”. This may make it difficult to determine whether a child has a cold, flu, COVID, or RSV. RSV vaccination helps prevent RSV illness. CDC recommends the best time to get vaccinated in in late summary and early fall, just before RSV usually starts to spread.
  • Who should receive the RSV vaccine?
    • People who are 32 to 36 weeks pregnant during September thru January. This timing helps pass maternal RSV antibodies to an infant at birth to help protect the infant from RSV.
    • Babies younger than 8 months of age during RSV season whose mothers did not get the RSV vaccine should get an RSV immunization that uses monoclonal antibodies to protect them from severe disease.
  • What vaccines are available?
    • Abrysvo: Abrysvo is a vaccine indicated for active immunization of pregnant individuals at 32 through 36 weeks gestational age for the prevention of lower respiratory tract disease (LRTD) and severe LRTD caused by RSV in infants from birth through 6months of age.
  • What other options are available for RSV prevention in infants that are not vaccines?
    • Clesrovimab: Clesrovimab is an antibody that is given as an injection to prevent RSV lower respiratory tract disease in neonates and infants who are born or entering their first RSV season.
    • Nirsevimab: Nirsevimab is also an antibody that is given as an injection to neonates and infants who are born or entering their first RSV season and children up to 24 months of age who remain vulnerable to severe RSV disease through their second RSV season.

Rotavirus

  • Rotavirus is common in infants and young children. Infection with the virus usually causes symptoms such as severe, watery diarrhea, vomiting, fever and stomach pain. The virus usually causes symptoms for 3-8 days. The virus is easily spread between family members and children at daycare centers. The best way to protect your child from this disease is vaccination and good handwashing practices.
  • Who should receive the rotavirus vaccine? This oral vaccine is usually given as a series of 2 to 3 doses of drops at the following ages:
    • 2, 4 months or
    • 2, 4 and 6 months
  • What vaccines are available?
    • Rota Teq (RV5): This vaccine is given as a series of 3 doses of drops at 2, 4 and 6 months.
    • Rotarix (RV1): This vaccine is given as a series of 2 doses of drops at 2 and 4 months.

Tetanus, Diphtheria and Pertussis

  • Tetanus is a disease caused by infection with the bacteria Clostridium tetani. Tetanus is a serious disease that causes lockjaw and can progress to seizures, difficult swallowing, involuntary muscle spasms, seizures, and difficulty breathing.
  • Diphtheria is a disease caused by a toxin is released by the Clostridium diphtheriae bacterium. The toxin can cause serious illness if it affects the respiratory system. The skin and other body parts can be affected. In the United States, this disease is almost always associated with international travel.
  • Pertussis, also known as whooping cough, is a very contagious respiratory illness caused by the Bordatella pertussis bacteria. It causes symptoms of a cold (runny nose, low-grade fever, and mild cough). The cough can progress to uncontrollable coughing fits. People with pertussis may make a high-pitched whoop sound when they inhale during these coughing fits. This may cause breathing problems. Contact a doctor immediately if struggling to breathe.
  • Who should receive vaccination against these diseases? Tetanus, Diphtheria and Pertussis vaccines are usually given in combination as a series of six shots during infancy and childhood at the following ages:
    • 2, 4 and 6 months
    • 15-18 months
    • 4-6 years
    • 11-12 years
  • What vaccines are available?
    • Diphtheria, Tetanus, and acellular pertussis (DTaP): Daptacel, Infanrix for infants and young children

Varicella (Chicken Pox)

  • Chicken pox is a very contagious (easily spread) disease caused by the varicella-zoster virus (VZV). It causes blister-like rash, itching, and fever. It usually causes mild illness. However, it can cause serious illness in infants and children who have weekended immune systems. Serious illness may require hospitalization.
  • Who should receive the Varicella vaccine? The Varicella vaccine is usually given as two shots during childhood at 12-15 months and 4-6 years of age.
  • What vaccines are available?
    • Varivax: This vaccine is approved for use in people 12 months or older.
    • ProQuad: This vaccine is a combination vaccine that also includes measles, mumps and rubella vaccines, and is approved for children 12 months to 12 years of age.
    • The Centers for Disease Control and Prevention’s (CDC) Advisory Committee on Immunization Practices (ACIP) recommends that toddlers through age three be immunized for varicella by standalone vaccination administered at the same time as the MMR vaccine, rather than the combination measles, mumps, rubella, and varicella (MMRV) vaccine.
    • The CDC Immunization Safety Office reports that healthy 12–23 months old toddlers have increased risk of febrile seizure seven to 10 days after MMRV vaccination compared to those given separate immunization for varicella and measles, mumps, and rubella (MMR). According to the CDC, the MMRV vaccine doubles the risk of febrile seizures without conferring additional protection from varicella compared to standalone vaccination.

What are the potential side effects of vaccines in infants and toddlers?

Who should not receive vaccines?

What should I do if my child experiences severe or persistent symptoms after receiving a vaccine?