PCV Vaccination for a 9-Month-Old Unvaccinated Child
Yes, a 9-month-old child with no prior vaccination history should absolutely receive PCV13 vaccine, following a specific 3-dose catch-up schedule. 1
Recommended Vaccination Schedule for This Child
For infants aged 7-11 months starting vaccination, administer 3 total doses of PCV13: 1
- First dose: Give immediately at the current visit (9 months)
- Second dose: Administer at least 4 weeks after the first dose (minimum interval) 1, 2
- Third dose (booster): Give at 12-15 months of age, at least 8 weeks after the second dose 1, 2
This schedule provides catch-up protection for children who missed the standard infant series that typically begins at 2 months of age. 1
Key Timing Considerations
The minimum interval between the first two doses is 4 weeks (not 8 weeks, which applies only to children ≥12 months). 1, 2 This allows for more rapid catch-up protection in this vulnerable age group.
The third dose must be given at 12-15 months AND at least 8 weeks after the second dose, whichever comes later. 1, 2 This booster dose is critical for long-term immunity and immunologic memory.
Safety and Efficacy
PCV13 is safe and highly effective when administered to children in this age group. 1 The vaccine can be given concurrently with other routine childhood vaccinations at separate injection sites. 1, 3
For premature infants, use chronologic age (not corrected age) for scheduling. 1 The 9-month-old should follow the same schedule regardless of gestational age at birth.
Special Circumstances
If this child has underlying medical conditions (sickle cell disease, asplenia, HIV infection, immunocompromising conditions, cochlear implant, or CSF leak), the same 3-dose schedule applies initially. 1, 4 However, these high-risk children will require additional doses of PCV13 and subsequent PPSV23 vaccination after age 2 years. 1, 3, 4
Common Pitfall to Avoid
Do not use the 2-dose schedule (which applies to children 12-23 months) for this 9-month-old child. 1 Children starting vaccination at 7-11 months require 3 doses total, not 2, because they need the additional primary series dose for adequate initial immune response before the booster. 1, 2
Do not delay vaccination further. Children aged 7-11 months remain at high risk for invasive pneumococcal disease, and even a single dose provides meaningful protection (56.8-64.6% effectiveness), with substantially higher protection after completing the series. 5