The Complete Childhood Vaccine Schedule (0-6 Years): Visit by Visit

Why the Vaccine Schedule Is Designed This Way

The childhood immunization schedule is developed by the Centers for Disease Control and Prevention (CDC), the American Academy of Pediatrics (AAP), and the American Academy of Family Physicians (AAFP). It’s reviewed and updated annually based on the latest research on vaccine safety, effectiveness, and disease epidemiology. The schedule is designed to provide protection as early as possible, when infants are most vulnerable to serious complications from vaccine-preventable diseases.

Birth to 15 Months: The Core Vaccine Series

Birth

• Hepatitis B (HepB) — First dose. Given before hospital discharge. Prevents hepatitis B infection, which can become chronic and lead to liver disease.

1-2 Months

• Hepatitis B (HepB) — Second dose. Given at 1-2 months.

2 Months

• DTaP — First dose. Protects against diphtheria, tetanus, and pertussis (whooping cough).
• IPV — First dose. Inactivated polio vaccine.
• Hib — First dose. Protects against Haemophilus influenzae type b, which can cause meningitis.
• PCV13 — First dose. Pneumococcal conjugate vaccine, protects against 13 strains of pneumococcal bacteria.
• RV — First dose. Rotavirus vaccine, given orally. Protects against severe rotavirus gastroenteritis.

4 Months

• DTaP — Second dose
• IPV — Second dose
• Hib — Second dose
• PCV13 — Second dose
• RV — Second dose (if RV1 brand; RV5 requires a third dose at 6 months)

6 Months

• DTaP — Third dose
• IPV — Third dose (optional per some schedules, given at 6-18 months)
• Hib — Third dose (if needed, depends on brand)
• PCV13 — Third dose
• RV — Third dose (if using RV5 brand)
• Hepatitis B (HepB) — Third dose (given at 6-18 months)
• Influenza — First dose, then annually. Children 6 months and older should receive the flu vaccine each year.

12-15 Months

• MMR — First dose. Measles, mumps, rubella vaccine.
• Varicella — First dose. Chickenpox vaccine.
• Hepatitis A (HepA) — First dose. Given at 12-23 months, with a second dose 6 months later.
• PCV13 — Booster (fourth dose)
• Hib — Booster (fourth dose, if needed)

15-18 Months

• DTaP — Fourth dose

2-6 Years: Booster and Catch-Up

2-3 Years

• Influenza — Annually
• Hepatitis A (HepA) — Second dose (if not yet given)

4-6 Years

• DTaP — Fifth dose (booster)
• IPV — Fourth dose (booster)
• MMR — Second dose
• Varicella — Second dose
• Influenza — Annually

Common Questions About Vaccines

Vaccine Safety: What the Evidence Shows

Vaccines are among the most rigorously tested medical products. Before a vaccine is licensed, it goes through multiple phases of clinical trials involving thousands of participants. After licensure, the FDA and CDC continue monitoring through the Vaccine Adverse Event Reporting System (VAERS) and the Vaccine Safety Datalink. Serious side effects are extremely rare. The most common side effects are mild and temporary: soreness at the injection site, low-grade fever, and fussiness.

The overwhelming scientific consensus is that the recommended vaccine schedule is safe and effective. Delaying or spreading out vaccines does not reduce the risk of side effects — it only prolongs the period during which your child is unprotected.

Building a Care Team

Your pediatric care team includes your pediatrician, lactation consultant, and other specialists as needed. Establish this relationship early and maintain regular well-child visits to monitor growth, development, and preventive care.

Trusting Your Instincts

While evidence-based guidance is essential, you know your baby best. If something feels wrong, do not hesitate to contact your pediatrician. Early evaluation is always preferable to waiting when it comes to infant health concerns.

Related: Childhood Vaccination Schedule Guide | Baby Vaccination Schedule 2-12 Months

📖 More from the Pediatrician’s Corner Hub: your complete pediatrician-reviewed guide to your baby’s first year — milestones, feeding, sleep, vaccines, common illnesses, and more

Clinical Insights on Infant Health: Evidence-Based Guidance for Common Concerns

In my pediatric practice, I have found that the line between normal infant variation and a genuinely concerning symptom is one of the hardest distinctions for parents to make. Let me share the clinical framework I use to help families navigate common health concerns in the first year.

The single most important principle in infant health assessment is understanding the concept of clinical trajectory. A single symptom — a fever, a rash, a cough — tells you very little in isolation. What matters is how the symptom develops over time. Is the fever rising or falling? Is the rash spreading or staying contained? Is the baby behaving differently — eating less, sleeping more, becoming less interactive — or are they acting essentially normal despite the symptom? In clinical medicine, we call this the “sick versus not-sick” assessment, and it is far more predictive of serious illness than any individual vital sign or symptom.

Fever in infants under 3 months is a medical urgency — not because the fever itself is dangerous, but because young infants have immature immune systems and cannot localize infections the way older children and adults can. A fever above 100.4°F (38°C) rectal in a baby under 3 months warrants a prompt evaluation, including blood work, urine culture, and often a lumbar puncture to rule out serious bacterial infection. This is not excessive caution; it is evidence-based practice that has dramatically reduced the mortality from neonatal sepsis over the past two decades. After 3 months of age, fevers are more common and less concerning, provided the baby is behaving well, drinking adequately, and has no other red flags such as difficulty breathing, persistent vomiting, or a stiff neck.

Rashes in newborns are another source of enormous anxiety that rarely requires intervention. I estimate that at least 60% of my urgent care visits for “rash” in infants under 6 months result in a diagnosis of a benign, self-limited condition. Erythema toxicum — the dramatic red blotches with white or yellow pustules that appear in the first days of life — looks alarming but is completely harmless and resolves without treatment. Neonatal acne, which peaks at 3-4 weeks, is caused by maternal hormone transfer and requires absolutely no intervention. Seborrheic dermatitis (cradle cap) is managed with gentle washing and, if needed, a very soft brush after oil application. The rashes I worry about are petechiae (tiny red spots that do not blanch with pressure, which may indicate a platelet disorder or serious infection), vesicles with fever (which could be herpes or varicella), and purpura (bruise-like spots that indicate bleeding under the skin). If you are unsure, the safest course is a picture sent to your pediatrician or a visit to the clinic.

Respiratory symptoms are the most common reason for pediatric acute care visits, and the clinical differentiation between a benign viral upper respiratory infection and a lower respiratory tract infection like bronchiolitis or pneumonia is critical. The key signs are work of breathing: nasal flaring, intercostal retractions (the skin pulling in between the ribs), subcostal retractions (pulling in below the rib cage), head bobbing, and grunting with each breath. A baby with a runny nose and a mild cough who is feeding well, sleeping reasonably, and has normal work of breathing can almost always be managed at home with nasal saline, suctioning, and a cool-mist humidifier. A baby with any of the above signs of increased work of breathing needs evaluation, as does any infant under 6 months with a temperature above 102°F and respiratory symptoms.

Gastrointestinal symptoms — spit-up, reflux, diarrhea, constipation — generate enormous parental concern and, in most cases, require only supportive management. The distinction between physiologic reflux (spit-up that is effortless, painless, and does not affect growth) and gastroesophageal reflux disease (GERD, which involves pain, feeding refusal, arching, and poor weight gain) is clinically important. Physiologic reflux affects nearly all infants to some degree and resolves spontaneously as the lower esophageal sphincter matures, typically by 12-18 months. GERD requires medical evaluation and, in some cases, pharmacologic treatment with acid-suppressing medications. The difference is in the baby’s experience of the reflux, not the volume of spit-up. A happy spitter does not need medication.

Trust your pediatrician, but also trust yourself. You see your baby every day. You know when something is different. If you find yourself thinking “this doesn’t seem right” — even if you cannot articulate why — call us. That instinct is almost never wrong.

Clinical Pearl: When Symptoms Warrant a Second Look

In pediatric practice, we teach parents to assess the “whole baby” rather than fixating on individual symptoms. A baby who has a fever but is smiling, making eye contact, feeding reasonably, and has normal skin color is far less concerning than a baby with a normal temperature who is lethargic, difficult to rouse, and not feeding. This concept — sometimes called clinical gestalt — is actually a more sensitive predictor of serious illness than any single vital sign or laboratory value in isolation. The most important tool in your parenting toolkit is not a thermometer or an app; it is your ability to observe whether your baby is acting like themselves. If your baby is behaving normally, you can generally monitor a mild symptom at home with symptomatic care. If your baby is not behaving normally — if they are unusually sleepy, fussy, or “off” — that is the time to call your pediatrician, even if you cannot pinpoint exactly what is wrong. Trust that instinct.

Clinical Pearl: The CDC’s Advisory Committee on Immunization Practices (ACIP) reviews the childhood immunization schedule annually through a rigorous evidence-based process. The 2-, 4-, and 6-month visit schedule aligns with the window of highest vulnerability to vaccine-preventable diseases while the immune system is still developing. Vaccines are 90-99% effective at preventing disease when administered on schedule — a single measles case can expose up to 90% of unvaccinated close contacts.