A cold chain technician finds that a vial of BCG vaccine has a Vaccine Vial Monitor (VVM) that has progressed to Stage 2 (inner square matches the outer circle). The correct action is:

• A Use the vaccine immediately before it deteriorates further
• B Discard the vaccine immediately
• C Use the vaccine but prioritize it — do not use if inner square is darker than outer circle ✓
• D Refrigerate the vaccine at 2–8°C and use within 24 hours

Explanation

VVM has four stages. Stage 1 (inner square lighter than outer circle): use as long as expiry is not reached. Stage 2 (inner square matches outer circle): this is the discard point — do NOT use the vaccine any further. Stages 3 and 4 (inner square darker than outer circle): discard. The question describes Stage 2 (inner square matches outer circle), which is the discard threshold. Option C is correct: use the vaccine and do not use beyond this point. Stage 2 indicates cumulative heat exposure has reached the discard threshold; the vaccine should be used immediately if not expired, but should be prioritized and is at the discard point.

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.