Baby Vaccine Schedule: Birth to 18 Months (CDC Recommended)

Birth: Hepatitis B — dose 1

The first vaccine most babies receive is the Hepatitis B vaccine (HepB), given within 24 hours of birth for healthy term newborns. Hepatitis B is a viral infection of the liver that can be transmitted from mother to child at delivery. In infants who acquire it perinatally, approximately 90% go on to develop chronic infection, which dramatically increases lifetime risk of liver cirrhosis and liver cancer.

Starting the series at birth provides protection before any possible exposure and takes advantage of the most responsive window for generating lasting immunity. If the mother is HBsAg-positive (carries the hepatitis B surface antigen), the baby also receives Hepatitis B immunoglobulin (HBIG) at a separate injection site within 12 hours of birth for immediate passive protection while the vaccine builds active immunity.

The birth dose is the first of a 3-dose series. All three doses are needed for full, long-lasting protection.

2 months: the first major combination visit

The 2-month visit is the busiest vaccine appointment in the first year. Maternal antibodies transferred during pregnancy wane around this time, leaving the baby vulnerable. The vaccines typically given at 2 months:

• DTaP: diphtheria, tetanus, and acellular pertussis (whooping cough). Pertussis is the most pressing concern — it can be severe and even fatal in young infants before the series is complete. This is why cocooning (ensuring all household members are vaccinated with Tdap) is recommended during pregnancy.
• IPV: inactivated poliovirus vaccine. Protects against all three types of poliovirus.
• Hib: Haemophilus influenzae type b — a major cause of meningitis and severe pneumonia in infants before the vaccine era.
• PCV15 or PCV20: pneumococcal conjugate vaccine — protects against Streptococcus pneumoniae, a leading cause of pneumonia, meningitis, and ear infections.
• RV: rotavirus vaccine, given orally. Rotavirus causes severe diarrhoea and vomiting and was a leading cause of infant hospitalization before the vaccine. The oral form is given in 2 or 3 doses depending on the brand.
• HepB dose 2: typically given between 1 and 2 months; may be combined with the 2-month visit.

Some of these are given as combination injections (e.g., Pediarix contains DTaP + IPV + HepB in one shot), reducing the total number of injections. Your pediatrician's office will use whatever combination products they have available.

4 months: booster doses

The 4-month visit consists primarily of second doses of the vaccines started at 2 months — because a single dose does not produce full protective immunity for most of these vaccines:

• DTaP dose 2
• IPV dose 2
• Hib dose 2
• PCV dose 2
• RV dose 2 (and dose 3 if using Rotateq)

The 4-month visit is often just as reaction-heavy as the 2-month visit in terms of post-vaccine fussiness and low-grade fever, since the immune system is mounting a secondary response. Having paracetamol available at home and planning for a quieter day or two is sensible.

6 months: third doses and first annual influenza vaccine

At 6 months, third doses of the core series vaccines are due:

• DTaP dose 3
• IPV dose 3
• Hib dose 3 (brand-dependent — some 3-dose Hib products skip the 6-month dose)
• PCV dose 3
• HepB dose 3 (if not already given between 1–2 months)
• RV dose 3 (Rotateq only — must be completed by 8 months 0 days)

Influenza vaccine: the first influenza vaccine is recommended at 6 months. Because babies under 9 months receiving influenza vaccine for the first time need two doses given 4 weeks apart, the 6-month visit is a good time to start. Annual flu vaccination is then recommended every fall thereafter.

Influenza in babies under 6 months can be severe; since they are too young for the vaccine, cocooning (vaccinating all household contacts) protects them indirectly during this window.

12–15 months: a new wave of vaccines

After the relative quiet of the 9-month well-child visit (which typically has no vaccines), the 12-15 month period brings several new vaccinations:

• MMR (measles, mumps, rubella): given at 12–15 months. The first of a 2-dose series. Maternal antibodies for measles persist until around 12 months, which is why the vaccine is not started earlier. Measles is one of the most contagious infectious diseases known and can cause severe complications including encephalitis and death.
• Varicella (chickenpox): given at 12–15 months, first of 2 doses. Chickenpox is typically mild but can cause serious complications including bacterial superinfection, pneumonia, and encephalitis.
• Hib dose 4: the final booster of the Hib series.
• PCV dose 4: the final booster of the pneumococcal series.
• HepA dose 1: the first of a 2-dose Hepatitis A series, recommended starting at 12 months and completing the second dose 6–18 months later.

The MMRV combination vaccine (ProQuad) combines measles, mumps, rubella, and varicella into one injection, but is associated with a slightly higher risk of febrile seizures at this age compared to separate MMR and varicella shots — discuss with your pediatrician which approach they use.

18 months: completing the primary series

The 18-month visit completes several series:

• DTaP dose 4: the fourth of five total DTaP doses. (The fifth is given at age 4–6 years before school entry.)
• IPV dose 4: same — a fifth dose is not routinely needed if the fourth was given at 4 years or older.
• HepA dose 2: completing the 2-dose hepatitis A series.
• Annual influenza vaccine: given each fall season.

After the 18-month visit, the next major vaccine cluster is at the 4–6 year pre-school entry visit (DTaP dose 5, IPV dose 4 if not already given, MMR dose 2, Varicella dose 2).

Mild reactions: what's normal vs. when to call

Expected reactions (not a reason to skip future doses):

• Soreness, redness, swelling, or a small lump at the injection site — usually resolves within 1–3 days. A cool cloth (not ice) applied gently can help.
• Low-grade fever (38–38.5°C / 100.4–101.3°F) for 24–48 hours
• Fussiness, crying more than usual on the day of vaccines
• Drowsiness or sleeping more than usual
• Reduced appetite on vaccine day

These are signs that the immune system is responding and building protection — they are expected and not harmful. Giving a weight-appropriate dose of paracetamol at the time of vaccination (pre-medication) or after, if the baby seems uncomfortable, is appropriate.

When to call your doctor or go to the ER:

• Fever above 40°C (104°F)
• Inconsolable crying lasting more than 3 hours
• A high-pitched, unusual cry
• Extreme drowsiness or difficulty waking
• Signs of an allergic reaction: hives, facial swelling, difficulty breathing (rare — usually within 15 minutes of vaccination, which is why you wait in the clinic)
• Seizure

Serious reactions to vaccines are extremely rare. The risks of vaccine-preventable diseases are far greater than the risks of the vaccines themselves.

Why the schedule exists and catch-up information

The timing of the CDC schedule is designed around the immunological window when each vaccine produces the best immune response while protecting against disease at the age when the disease poses the greatest risk. Starting earlier or later than scheduled may reduce the vaccine's effectiveness or leave the baby unprotected during a vulnerable period.

If your baby misses a vaccine appointment, it is important to catch up as soon as possible. In general, you never need to restart a series from scratch — pick up where you left off. The CDC publishes official catch-up schedules at cdc.gov/vaccines. Your pediatrician can review your baby's records and create a personalized catch-up plan.

Vaccines are not just about individual protection — they also reduce community transmission, protecting those too young or medically unable to be vaccinated (e.g., infants under 6 months who cannot yet receive influenza vaccine, babies with certain immune conditions).

How Bebblo helps you track vaccine appointments

Keeping a log of which vaccines your baby has received, on which dates, and at which clinic is the kind of detail that matters when you move, change pediatricians, or need to provide school enrollment records. Bebblo's notes section lets you record each visit with timestamps and custom entries — a simple but practical way to keep your baby's health history in one place.

This article is for general guidance and reflects the CDC/ACIP schedule. Vaccine availability and schedules vary by country. Always follow your pediatrician's and local health authority's recommendations.

Frequently asked questions

What vaccines does my baby get at birth?

At birth, healthy newborns receive the first dose of the Hepatitis B (HepB) vaccine, typically within 24 hours of delivery. If the mother is HBsAg-positive, the baby also receives Hepatitis B immunoglobulin (HBIG) at the same time for immediate passive protection.

Why do babies get so many vaccines at the 2-month visit?

The 2-month visit is the first major combination vaccine visit because maternal antibody protection fades around this age. The vaccines given protect against diseases that pose the greatest risk in early infancy. Research shows the immune system of a healthy 2-month-old handles multiple antigens simultaneously without problem.

What are normal reactions after baby vaccines?

Common and expected reactions include soreness or redness at the injection site, low-grade fever (38–38.5°C), fussiness, and increased sleepiness for 24–48 hours. These indicate the immune system is responding normally. See your doctor if fever exceeds 40°C, the baby is inconsolable for more than 3 hours, or there is severe swelling at the injection site.

Can my baby catch up on missed vaccines?

Yes. Missed doses can generally be given at subsequent visits without restarting the series from the beginning. The CDC and AAP publish catch-up immunization schedules. Speak to your pediatrician, who can create a personalized catch-up plan.

Why the Vaccine Schedule Is Designed the Way It Is

The timing of childhood vaccines is not arbitrary. The CDC Advisory Committee on Immunization Practices (ACIP) and the American Academy of Pediatrics (AAP) Committee on Infectious Diseases set the schedule based on three interconnected principles:

• Vulnerability windows. The schedule protects babies at the ages when specific diseases are most dangerous. Whooping cough (pertussis), for example, is most deadly in the first six months of life — so DTaP starts at 2 months, as soon as an infant's immune system is mature enough to mount a response.
• Immune system readiness. Vaccines are timed to when babies can generate strong, lasting immune responses. Too early and the maternal antibodies still present in a newborn's blood may interfere. Too late and the protection window is missed.
• Herd immunity thresholds. Community-level protection requires that a high percentage of the population be immune. The schedule is designed to reach those thresholds as fast as possible, protecting newborns who are too young to be vaccinated and immunocompromised individuals who cannot be vaccinated.

The 2026 CDC immunization schedule is the result of ongoing evidence review by ACIP, incorporating decades of post-licensure safety data, immunogenicity studies, and real-world effectiveness monitoring. When the schedule changes — as it does periodically — it reflects new evidence, not shifting preferences.

Complete Vaccine Schedule: Birth to 24 Months

The table below reflects the 2026 CDC recommended immunization schedule for children 0–24 months, consistent with AAP guidance. Vaccine names use standard abbreviations: DTaP (diphtheria, tetanus, acellular pertussis), Hib (Haemophilus influenzae type b), IPV (inactivated poliovirus), PCV15/20 (pneumococcal conjugate), RV (rotavirus), MMR (measles, mumps, rubella), HepB (hepatitis B), HepA (hepatitis A).

What Each Vaccine Protects Against

HepB — Hepatitis B

Hepatitis B is a viral infection that attacks the liver. Infants are particularly vulnerable because infection in the first year of life progresses to chronic infection in up to 90% of cases, compared to 5–10% in adults. Chronic hepatitis B can lead to cirrhosis and liver cancer decades later. The vaccine series is 95%+ effective at preventing infection.

DTaP — Diphtheria, Tetanus, Acellular Pertussis

DTaP protects against three diseases. Diphtheria causes a thick membrane in the throat that can block breathing. Tetanus causes uncontrollable muscle spasms. Pertussis (whooping cough) causes violent coughing fits — in infants, it can cause apnea (breathing pauses) and is fatal in about 1 in 100 babies under 2 months who get it. The series requires 5 total doses through age 6, with the first 3 given in the first 6 months of life.

Hib — Haemophilus influenzae type b

Despite its name, Hib has nothing to do with influenza. It's a bacterial infection that was the leading cause of bacterial meningitis in children under 5 before the vaccine was introduced. Hib meningitis kills 3–6% of affected children and causes permanent brain damage, hearing loss, or other disabilities in another 15–30%. The vaccine has reduced Hib disease by over 99% in the US.

IPV — Inactivated Poliovirus Vaccine

Polio is a viral disease that can cause permanent paralysis. The US switched from the live oral poliovirus vaccine to the inactivated (killed-virus) IPV in 2000. Wild poliovirus has been eradicated from the Western Hemisphere since 1991, but vaccination must continue because the virus still circulates in parts of South Asia and Africa. The 4-dose IPV series is completed by 4–6 years, with the first 2–3 doses given in the first 6 months.

PCV15/PCV20 — Pneumococcal Conjugate Vaccine

Streptococcus pneumoniae bacteria cause pneumonia, meningitis, bloodstream infections, and ear infections. Young children are particularly susceptible. PCV15 covers 15 bacterial serotypes; PCV20 covers 20. Either is acceptable per the current schedule. The series has dramatically reduced invasive pneumococcal disease in children and (through herd immunity) in unvaccinated adults.

RV — Rotavirus Vaccine

Rotavirus is the most common cause of severe diarrhea and vomiting in infants and young children worldwide. Before the vaccine, rotavirus caused an estimated 55,000–70,000 hospitalizations per year in the US. The oral vaccine (given as liquid drops) is highly effective at preventing severe disease. It must be started by 14 weeks 6 days and completed by 8 months — there is a specific age cutoff because of a very small risk of intussusception (bowel obstruction) associated with older first doses.

MMR — Measles, Mumps, Rubella

Measles is among the most contagious diseases known — one infected person can spread it to 12–18 others in an unvaccinated population. It kills approximately 1 in 1,000 infected children in developed countries and can cause encephalitis and permanent brain damage. Rubella during pregnancy causes severe birth defects (congenital rubella syndrome). The MMR vaccine is 97% effective against measles after two doses.

Varicella — Chickenpox

Before the vaccine, roughly 4 million Americans got chickenpox every year, with 10,000–13,000 hospitalizations and 100–150 deaths annually. The varicella vaccine is about 90% effective against infection and 99% effective against severe disease. The two-dose series (at 12 months and 4–6 years) provides substantially better protection than a single dose.

HepA — Hepatitis A

Hepatitis A causes liver inflammation and is spread through contaminated food and water. While rarely fatal in children, it can cause severe illness for weeks, and infected children (who often have mild or no symptoms) frequently spread it to adults who are more likely to become seriously ill. The 2-dose series (beginning at 12 months, completed by 23 months) provides long-lasting protection.

Influenza (Flu)

Influenza causes an estimated 7,000–26,000 pediatric hospitalizations and up to 180 child deaths in the US every year. Children under 5, especially under 2, are at highest risk of serious complications. The vaccine is reformulated each year to match circulating strains. First-time infant recipients need two doses, one month apart; subsequent years require only one annual dose.

What to Expect on Vaccine Day

Knowing what's normal after vaccines reduces anxiety and helps you respond appropriately if your baby is uncomfortable.

During the visit

Most injections are given in the thigh for infants under 12 months, switching to the upper arm as toddlers get older. Combination vaccines reduce the number of shots — your baby may receive 2–4 injections at the 2-month, 4-month, and 6-month visits. The rotavirus vaccine is given orally (a liquid squeezed into the mouth). The visit typically takes 20–30 minutes total, with 15 minutes of post-vaccination observation.

Normal reactions in the first 1–3 days

• Soreness and redness at the injection site — normal inflammatory response. A cool, damp cloth provides comfort; never apply heat.
• Low-grade fever (under 101°F / 38.3°C) — a sign the immune system is responding. Acetaminophen (Tylenol) can be given for comfort if your baby is uncomfortable, but is not required. Do not give ibuprofen to babies under 6 months.
• Fussiness and crying — very common in the first 12–24 hours. Extra feeding, holding, and comfort usually help.
• Drowsiness — babies often sleep more than usual after vaccine visits. This is normal.
• Small, firm lump at the injection site — can persist for several weeks and is harmless.

Myth-Busting: Vaccines and Autism

The claim that vaccines — specifically the MMR vaccine — cause autism is one of the most thoroughly investigated and definitively refuted hypotheses in modern medicine. Understanding the history helps parents evaluate information critically.

The Wakefield study and its retraction

In 1998, Andrew Wakefield and 12 co-authors published a small case series in The Lancet suggesting a possible link between the MMR vaccine and autism. The study included only 12 children. By 2004, 10 of the 13 original authors had retracted the paper's interpretation. In 2010, The Lancet fully retracted the paper after an investigation by the UK General Medical Council found that Wakefield had manipulated data, had undisclosed financial conflicts of interest (he was being paid by lawyers seeking to sue vaccine manufacturers), and had subjected children to invasive procedures without ethical approval. Wakefield lost his medical license.

The evidence that followed

Wakefield's retracted paper sparked hundreds of follow-up studies, none of which found a link:

• A 2019 Danish cohort study of 650,000+ children found no increased risk of autism among MMR-vaccinated children, including in subgroups of children at higher genetic risk for autism.
• A 2014 meta-analysis of 1.2 million children found no relationship between vaccines and autism.
• Studies examining the removal of thimerosal (a mercury-based preservative) from vaccines in the early 2000s showed no subsequent decrease in autism rates — autism rates continued to rise, and thimerosal was never used in MMR vaccines.
• The CDC's Vaccine Safety Datalink continues to monitor over 9 million insured individuals for vaccine safety signals. No autism signal has been detected.

Why autism diagnoses often appear near vaccine milestones

The apparent timing is coincidental. Autism spectrum disorder symptoms typically become more apparent between 18 and 24 months — the same age when toddlers receive the MMR vaccine and several other vaccines. This coincidence creates a powerful cognitive bias (post hoc ergo propter hoc — "after this, therefore because of this"), but correlation is not causation. Autism is now understood to have genetic and early neurodevelopmental origins that precede birth, not to be triggered by vaccines given in the second year of life.

The scientific consensus is clear: vaccines do not cause autism. The benefit-risk calculation — preventing serious, potentially fatal infectious diseases vs. a risk that has been looked for extensively and never found — makes following the recommended immunization schedule the evidence-based choice for your baby's health.

If You Fall Behind: Catch-Up Schedules

Life happens — illness, missed appointments, or parental hesitancy can result in a gap in your baby's immunization record. The CDC publishes a separate catch-up immunization schedule specifically for children who are behind, and the key principles are reassuring:

You never start over

Completed doses count. If your baby received 2 of 3 HepB doses and you're now 4 months late on the 3rd, your pediatrician simply gives dose 3 at the next visit. Minimum intervals between doses must be observed (usually 4 weeks minimum for most series), but the series continues from where it left off.

Age limits exist for certain vaccines

• Rotavirus: Must be started by 14 weeks 6 days and all doses completed by 8 months (24 weeks). This age cutoff is strictly enforced because older first doses carry a slightly increased risk of intussusception.
• MMR and Varicella: Should not be given before 12 months; no upper age limit for catch-up.
• Hib: Not routinely given after age 5 (most children are immune by natural exposure or previous vaccination by then).

Your pediatrician will build a catch-up plan

At any visit, your doctor or nurse can access the current catch-up schedule tables and create a personalized plan. No judgment — the goal is protection, and starting later is always better than not starting at all. Many pediatric practices use electronic reminder systems; Bebblo's vaccine tracker can serve as a parallel reminder you control directly.

Preparing for Vaccine Visits

A little preparation makes vaccine appointments smoother for both baby and parents:

• Bring your vaccine record. Your pediatrician maintains the official record, but having your own copy — physical card or digital — lets you confirm doses at any visit and keeps you informed if you see a different provider.
• Feed your baby beforehand. A fed baby is a calmer baby. Nursing or bottle-feeding immediately after injections has been shown in research to reduce pain response.
• Ask about Vaccine Information Statements (VIS). Pediatricians are legally required to provide a VIS for each vaccine given. These one-page CDC documents explain benefits and risks in plain language.
• Dress for easy access. Thighs and upper arms need to be accessible. Onesies and easy-snap outfits are ideal for vaccine visits.
• Plan a quiet day after. Your baby may be fussier or sleepier than usual. Having a lighter-than-usual schedule for the rest of the day makes it easier to respond to their needs.

Related Guides

• Well-Baby Visit Checklist: What Happens at Each Checkup (Birth to 18 Months)
• Baby Fever: When to Worry & When to Call Doctor
• Newborn weight loss and gain: what's normal in the first weeks

Track your baby's health milestones with Bebblo

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Track Vaccines with Bebblo

Bebblo's vaccine history tracker lets you log each immunization as it happens — with the vaccine name, date, and dose number. You can see at a glance which vaccines are complete, which are upcoming, and which require a follow-up dose. When you bring Bebblo's pre-visit summary to your well-baby visits, your pediatrician sees your vaccine log alongside feeding patterns, sleep data, and developmental milestones — all in one place.

No more digging through paper vaccine cards or trying to remember when the last flu shot was. Everything is timestamped and organized, so you're prepared for every appointment and can share accurate information with any provider your baby sees.

Read our companion guide: Well-Baby Visit Checklist — What to Track and Ask Your Pediatrician.

Core tracking is free. No account required.

This article is for general informational purposes only and does not replace advice from your doctor or pediatrician. Always consult your child's healthcare provider for personalized vaccine guidance. Immunization schedules are updated annually by the CDC and AAP — confirm the current schedule at cdc.gov/vaccines or with your pediatrician.