Recommended Vaccine for 4th DTaP Dose After Pentacel
Use Pentacel (DTaP-IPV/Hib) for the 4th dose at 15-18 months of age, as it is specifically licensed and indicated for this purpose. 1
Primary Recommendation
- Pentacel is FDA-licensed for use as a 4-dose series at ages 2,4,6, and 15-18 months, making it the appropriate choice for the 4th dose after completing the first three doses with the same vaccine. 1
- The CDC explicitly states that Pentacel is indicated for use at ages 2,4,6, and 15-18 months, which directly includes the 4th dose timing. 1
- The 4th dose may be administered as early as 12 months of age if there is concern about missing a vaccination opportunity, provided 6 months has elapsed since the 3rd dose. 1
Why Not Other Options
Kinrix Cannot Be Used for the 4th Dose
- Kinrix is exclusively recommended as the 5th dose of DTaP (not the 4th dose) and is only licensed for children aged 4-6 years. 2
- The CDC explicitly notes that Kinrix's age restriction (minimum age 4 years) means it cannot be used for the 4th dose, which is typically given at 15-18 months. 2
- Kinrix should only be used when the first 3 DTaP doses were Infanrix and/or Pediarix, and the 4th DTaP dose was Infanrix. 2
Age Limitations Are Critical
- Pentacel is only licensed through age 4 years (specifically up to 4 years, 364 days) and cannot be administered on or after the 5th birthday. 3
- This age restriction exists because Pentacel contains the Hib component, which is not indicated beyond age 4 years in healthy children. 3
Alternative if Pentacel Is Unavailable
- Daptacel is a suitable alternative for the 4th dose at 15-18 months if Pentacel is unavailable. 2
- While the same manufacturer's DTaP vaccine should be used throughout the series whenever feasible, vaccination should never be deferred if the specific brand previously administered is unavailable or unknown. 1, 2
Important Clinical Caveats
Inadvertent Administration
- If Kinrix is inadvertently administered for the 4th dose, the dose should be counted as valid and does not need to be repeated, provided minimum interval requirements have been met. 2
- If Pentacel is inadvertently administered to children aged >5 years, it should be counted as a valid dose. 1
Dosing Intervals
- The preferred interval between doses is 8 weeks, but a minimum interval of 4 weeks is acceptable if an accelerated schedule is needed. 1
- The 4th dose requires a minimum of 6 months elapsed since the 3rd dose if given early (at 12 months). 1
IPV Considerations
- When Pentacel doses are administered at 2,4,6, and 12-18 months, this provides 4 valid doses of IPV, which can complete the IPV series under accelerated circumstances. 1