During a cold chain assessment in a PHC, a VVM (Vaccine Vial Monitor) on a pentavalent vial shows that the inner square is slightly darker than the outer ring but the two are still clearly distinguishable. The correct interpretation and action is:

• A The vaccine has reached discard point Stage 3; do not use
• B VVM at Stage 1 (initial state); store and use normally
• C VVM is at Stage 2 (use with caution but use first); vaccine can be used but should be prioritized ✓
• D VVM is at Stage 4 (past discard point); return to cold chain

Explanation

VVM stages: Stage 1 = inner square lighter than outer ring (use); Stage 2 = inner square matches outer ring (use immediately — 'use first' priority); Stage 3 = inner square darker than outer ring but still distinguishable (do NOT use — reached discard point); Stage 4 = inner square completely dark (do not use — well past discard point). In this scenario the inner square is slightly darker but still distinguishable, which corresponds to Stage 3 — the discard point has been reached and the vaccine must not be used.

Reference: Park's Textbook of Preventive and Social Medicine, 27th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.