The Vaccine Vial Monitor (VVM) inner square has become DARKER than the outer circle. What action should be taken?

• A Use the vaccine immediately if still within expiry date
• B Discard the vaccine and do not use it ✓
• C Return to district cold chain officer for re-testing
• D Use for older children only; discard for infants

Explanation

The VVM endpoint is reached when the inner square becomes as dark as or darker than the outer circle, indicating irreversible cumulative heat damage. At this stage the vaccine must be discarded regardless of expiry date. VVM stages: Stage 1 (square lighter than circle) = use; Stage 2 (square matches circle) = do not use, discard; Stage 3 (square darker than circle) = discard. The VVM is read before each vaccination and protects patients from using potency-compromised vaccines.

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.