Recommended Childhood Immunization Schedule
Healthcare providers should follow the CDC/AAP/AAFP-approved immunization schedule that begins at birth with hepatitis B vaccine and continues through age 18 years, with specific vaccines administered at designated ages to maximize protection during periods of greatest vulnerability to vaccine-preventable diseases. 1
Birth to 6 Months
At Birth
- Hepatitis B vaccine must be administered before hospital discharge to all medically stable newborns weighing ≥2,000 g, as this minimizes risk from maternal testing errors and household exposures while increasing series completion rates. 1
- Only monovalent hepatitis B vaccine should be used for the birth dose; combination vaccines can be used for subsequent doses. 1
- Infants born to HBsAg-positive mothers require both hepatitis B vaccine and HBIG within 12 hours of birth regardless of birth weight, and should be tested for HBsAg and anti-HBs at 9-15 months. 2, 1
At 2 Months
- Administer the following vaccines simultaneously: 1
- Hepatitis B (second dose)
- Rotavirus (first dose - must be initiated between 6-14 weeks of age)
- DTaP (first dose)
- Haemophilus influenzae type b/Hib (first dose)
- Pneumococcal conjugate/PCV (first dose)
- Inactivated poliovirus/IPV (first dose)
At 4 Months
- Repeat the 2-month vaccines (second doses of Rotavirus, DTaP, Hib, PCV, and IPV). 1
At 6 Months
- Administer: 1
- Hepatitis B (third dose, completing the series at 6-18 months)
- Rotavirus (third dose if using RotaTeq; second dose if using Rotarix)
- DTaP (third dose)
- Hib (third dose - not needed if PRP-OMP was used)
- PCV (third dose)
- Influenza vaccine (first dose if during flu season; requires two doses separated by at least 4 weeks for first-time recipients under 9 years)
12-18 Months
At 12-15 Months
- Administer: 1
- MMR (first dose)
- Varicella (first dose)
- Hib (fourth/final dose - must be given after 12 months of age)
- PCV (fourth dose)
At 12-23 Months
- Hepatitis A vaccine (first dose, with second dose 6 months later). 1
At 15-18 Months
- DTaP fourth dose (can be given as early as 12 months if 6 months have elapsed since the third dose). 1
4-6 Years (Preschool Boosters)
- Administer the following before kindergarten entry: 1
- DTaP (fifth/final dose)
- IPV (fourth/final dose)
- MMR (second dose)
- Varicella (second dose)
11-12 Years (Adolescent Visit)
- Administer: 1, 3
- Tdap (single adolescent booster dose)
- HPV vaccine (two-dose series, second dose 6-12 months after first)
- Meningococcal ACWY vaccine (first dose, with booster at age 16)
Critical Timing Principles
Why This Schedule Exists
- The vaccination schedule balances maternal antibody interference with the urgent need to establish infant immunity during the period of maximum vulnerability. 1
- Starting at 6 weeks allows the infant's immune system to generate protective antibodies as maternal protection declines. 1
- Multiple doses spaced 4-8 weeks apart are necessary because a single dose rarely produces adequate or sustained antibody levels in young infants. 1
- The three-dose primary series achieves seroconversion rates of 96-100% when followed correctly. 1
Rotavirus Vaccine Constraints
- Rotavirus vaccination has strict age restrictions: must be initiated between 6-14 weeks of age and completed by 8 months due to theoretical increased risk of intussusception if started later. 1, 4
Catch-Up Immunization
For Children Starting Late or Behind Schedule
- Never restart a vaccine series regardless of time elapsed between doses - simply continue from where the child left off. 4
- Minimum intervals must be respected, but longer-than-recommended intervals do not reduce final antibody concentrations or require additional doses. 4
- Administer all age-appropriate vaccines simultaneously at separate anatomic sites to maximize protection and minimize visits. 4
Minimum Intervals for Catch-Up
- DTaP, IPV, Hepatitis B second doses: 4 weeks after first dose 4
- MMR second dose: 4 weeks after first dose 4
- Varicella second dose: 3 months after first dose (can be 4 weeks for catch-up) 4
- Hepatitis B third dose: At least 8 weeks after second dose AND at least 16 weeks after first dose AND not before 24 weeks of age 4
- Hepatitis A second dose: 6 months after first dose 4
- DTaP fourth dose: 6 months after third dose AND after age 4 years for final dose 4
Age-Specific Catch-Up Simplifications
- For healthy children ≥24 months: Single PCV dose is sufficient 4
- For healthy children ≥15 months: Single Hib dose is sufficient 4
- Rotavirus is NOT indicated for children who have reached 15 weeks of age without starting the series 4
Annual Vaccination
- Influenza vaccine should be administered annually beginning at 6 months of age. 2, 1
- Children under 9 years receiving influenza vaccine for the first time need two doses separated by at least 4 weeks. 1
Common Pitfalls to Avoid
- Do not delay the birth dose of hepatitis B vaccine - errors in maternal testing or household exposures can occur, and early vaccination increases series completion. 1
- Do not start rotavirus vaccine after 14 weeks 6 days of age due to intussusception risk. 1, 4
- Do not give the final DTaP dose before age 4 years - it will not provide adequate long-term protection. 1
- Do not use combination vaccines containing hepatitis B for the birth dose - only monovalent hepatitis B is appropriate. 1
- Do not withhold simultaneous vaccine administration - multiple vaccines can and should be given at the same visit when indicated. 4
Current Schedule Access
- The most current immunization schedules are available at: 2
- CDC website: www.cdc.gov/vaccines/schedules/hcp/child-adolescent.html
- AAP Red Book Online: http://redbook.solutions.aap.org/SS/Immunization_Schedules.aspx
- These schedules are revised annually to reflect current vaccine formulations and recommendations. 2
Adverse Event Reporting
- Clinically significant adverse events following immunization must be reported to the Vaccine Adverse Event Reporting System (VAERS). 2, 1
- Access VAERS at www.vaers.hhs.gov or call 800-822-7967. 2