CDC Catch‑Up Immunization Guidelines for Children Around 2 Years of Age

Immediate Catch‑Up Vaccines (at the first visit)

Administer DTaP as the next dose in the series (dose 3 or 4) provided at least a 4‑week interval has elapsed since the previous dose; the series is not restarted. [1][2]
Give IPV as the next dose in the series (dose 3 or 4); a minimum 4‑week interval is required between doses 1‑2 and 2‑3, with an 8‑week interval preferred for dose 3. 3
Provide Hib as the next dose (dose 3 or 4) to complete the primary series; if the PRP‑OMP schedule is used, only two doses at 2 months and 4 months are needed before the booster. [1][2]
Administer PCV as the next dose (dose 3 or 4); for children 24–59 months who have received fewer than three doses, give two catch‑up doses at least 8 weeks apart. 1
Initiate Hepatitis A vaccination (dose 1) at age ≥12 months, with the second dose scheduled ≥6 months later. 4

Schedule the final DTaP booster (dose 5) at age ≥4 years, ensuring at least a 6‑month interval since dose 4. 1
Plan the final IPV dose (dose 4) at age ≥4 years, with a minimum 6‑month interval after dose 3. 3
Give the Hib booster at 12–15 months if not already administered; no further Hib doses are required thereafter. 1
Provide the second PCV catch‑up dose 8 weeks after the first catch‑up dose when the child had received fewer than three prior doses. 1

Start or complete the 3‑dose Hepatitis B series (0, 1–2, and 6–18 months) if any doses were missed. 2
Offer annual influenza vaccination beginning at 6 months of age; children receiving it for the first time need two doses ≥4 weeks apart. 1
Administer varicella vaccine (dose 1) either concurrently with MMR or separated by ≥28 days if given separately. 2
Give Hepatitis A dose 2 exactly 6 months after the first dose. 4

DTaP: 4 weeks between doses 1‑2, 2‑3, 3‑4; dose 4 requires ≥6 months after dose 3; dose 5 at age ≥4 years. 1
IPV: 4 weeks between doses 1‑2 and 2‑3; ≥6 months between doses 3‑4; dose 4 at age ≥4 years. 3
PCV (catch‑up): 8 weeks between doses for children 12–59 months. 1

Do not administer a dose before the minimum interval; such a dose is invalid and must be repeated. 2
Avoid accelerated schedules (using minimum intervals) in infants younger than 6 months unless specifically indicated, as they are associated with lower seroconversion rates. 3
Ensure final booster doses: DTaP dose 5 and IPV dose 4 must be given at age ≥4 years regardless of the number of prior doses. [3][1]

The American Academy of Pediatrics recommends administering DTaP/DTP, IPV, Hib, and PCV vaccines immediately to an 8-month-old child who has only received birth vaccinations, following minimum interval guidelines to rapidly achieve protection against vaccine-preventable diseases 5, 6, 7, 8, 9, 10
The Centers for Disease Control and Prevention suggests that all indicated vaccines should be administered simultaneously at separate injection sites during this visit, increasing the probability of achieving timely protection and reducing the risk of the child not returning for subsequent doses 5, 6

The recommended follow-up schedule includes administering DTaP/DTP, IPV, Hib, and PCV vaccines at 9 months, with subsequent doses administered at 10 months and 12-15 months, following minimum interval guidelines 5, 6, 7, 8, 9, 10
The schedule also includes administering MMR and Varicella vaccines at 12 months, and a booster dose of Hib at 12-15 months 9, 11, 12

A vaccine series does not need to be restarted regardless of the time elapsed between doses, and the child should continue from where they left off, not start over 5, 6
Minimum intervals must be respected, and doses administered less than the minimum interval should not be considered valid 5, 6

The American Academy of Pediatrics recommends administering annual influenza vaccine starting at 6 months of age, with 2 doses separated by ≥4 weeks for children receiving influenza vaccine for the first time 11, 13, 14
Hepatitis A vaccine should be administered starting at 12 months of age in 2 doses separated by at least 6 months 11, 12