Catch-Up Immunization Schedules

Catch-up immunization is required for children who have fallen behind schedule — whether due to illness, missed appointments, parental decision, or immigration. The fundamental principle is simple but counterintuitive for many nurses: once you have started, you continue from where you are — you never restart the series no matter how long the gap. For the REx-PN exam, catch-up questions typically involve: (1) a child who has been behind on a series asking what to do next; (2) a scenario with a time gap between doses asking whether to restart or continue; (3) an age-specific question about which vaccine formulation to use in older children; or (4) a scenario about rotavirus in an older infant. On the exam, writers often pair stable-sounding options with unstable data—notice the mismatch before you commit. If the stem names a license or role, reread that line; scope errors are classic trap answers even when the clinical topic is familiar. Run a 60-second scan: breathing work and oxygenation, perfusion and end organs, neuro baseline, likely infection sources, and devices that can fail quietly. When two...