A 6-month-old infant from a rural area in Madhya Pradesh presents to the primary health centre for routine immunisation. The mother reports that the child received BCG and OPV-0 at birth, but missed the 6-week vaccinations due to illness. On examination, the child is clinically well with no contraindications to vaccination. What is the most appropriate next step in management?

Explanation

## Management of Delayed Immunisation in UIP **Key Point:** When a child presents late for immunisation, the principle is to **catch up without restarting** — administer all due vaccines at the current visit (provided no contraindications exist) and continue with the remaining schedule without repeating doses already given. ### Universal Immunisation Programme (UIP) — Catch-Up Rule The UIP guidelines emphasize **no need to restart the series** if there is a gap in the schedule. A child who has received BCG and OPV-0 at birth and now presents at 6 months should: 1. Receive all vaccines due at 6 weeks, 10 weeks, and 14 weeks in a **single visit** (or over 2–3 visits if spacing is preferred for safety monitoring). 2. Continue with the standard schedule thereafter. 3. **Not repeat** BCG or OPV-0, as they have already been administered. ### Why This Approach? | Principle | Rationale | | --- | --- | | **Catch-up without restart** | Minimizes further delays; ensures timely protection against vaccine-preventable diseases | | **No dose repetition** | Previous doses are immunologically valid; repeating wastes resources and increases adverse event risk | | **Accelerated spacing allowed** | Minimum intervals between doses may be shortened in catch-up scenarios (e.g., 4 weeks instead of 6) | | **Completion priority** | The goal is to complete the primary series as soon as possible | **High-Yield:** The UIP does **not** require restarting a series due to missed doses. A child who has received dose 1 but missed doses 2 and 3 should receive both at the next visit and continue normally. **Clinical Pearl:** In resource-limited settings, deferring vaccinations (option B) increases the risk of disease outbreaks and is not recommended unless there is a genuine contraindication. ### Why Spacing Matters While the child could receive all three vaccines (DPT-1, IPV-1, PCV-1) at once, OPV-1 can also be given at the same visit. There is **no immunological reason** to defer OPV-1 by 2 weeks (option A) — all inactivated and live vaccines can be co-administered. **Mnemonic:** **CATCH-UP** — **C**ontinue without restart, **A**dminister all due vaccines, **T**iming: accelerate if needed, **C**omplete the series, **H**old no doses, **U**se standard intervals thereafter, **P**rioritize protection.