A 6-month-old infant from rural India is brought for immunisation review. The child has received all primary series vaccines on schedule. Which feature best distinguishes Pneumococcal Conjugate Vaccine (PCV) from Haemophilus influenzae type b (Hib) vaccine in the IAP immunisation schedule?

Explanation

## Distinguishing PCV from Hib in IAP Schedule ### Pneumococcal Conjugate Vaccine (PCV) Schedule **Key Point:** PCV follows a 3+1 schedule with the booster administered earlier than Hib. - Primary series: 3 doses at 6, 10, 14 weeks - Booster dose: 12–15 months (second year of life) - Total: 4 doses - Protects against 13 serotypes of *Streptococcus pneumoniae* ### Haemophilus influenzae type b (Hib) Vaccine Schedule **Key Point:** Hib also follows a 3+1 schedule but with a later booster timing. - Primary series: 3 doses at 6, 10, 14 weeks - Booster dose: 18–24 months (second year of life, but later than PCV) - Total: 4 doses - Protects against *Haemophilus influenzae* type b only ### Comparison Table | Feature | PCV | Hib | |---------|-----|-----| | **Primary doses** | 3 (at 6, 10, 14 weeks) | 3 (at 6, 10, 14 weeks) | | **Booster timing** | 12–15 months | 18–24 months | | **Total doses** | 4 | 4 | | **Serotypes covered** | 13 | 1 | | **Route** | Intramuscular | Intramuscular | | **Catch-up schedule** | Yes (up to 5 years) | Yes (up to 5 years) | **High-Yield:** The most practical discriminator in the IAP schedule is the booster timing: PCV booster at 12–15 months vs. Hib booster at 18–24 months. This is a high-yield fact for exam questions. **Mnemonic:** **PCV-EARLY, Hib-LATE** — PCV booster comes earlier (12–15 months) than Hib booster (18–24 months). **Clinical Pearl:** Both are conjugate vaccines and both require 4 total doses, but the staggered booster schedule allows for separate administration windows and reduces the injection load at any single visit. [cite:IAP 2023 Immunisation Guidelines]