The Vaccine Vial Monitor (VVM) on a vaccine vial shows an inner square DARKER than the outer circle. The correct action is to:

• A Use the vaccine as it is still within potency
• B Check expiry date and use if not expired
• C Store at -20°C and recheck in 24 hours
• D Discard the vaccine and do not use it ✓

Explanation

The VVM (Vaccine Vial Monitor) is a heat-sensitive label attached to vaccines. When the inner square is lighter than the outer circle (stages 1 and 2), the vaccine can be used. When the inner square matches the outer circle (stage 3) — it is at the discard point; STOP using when the inner square is darker than the outer circle (stage 4). Once the VVM reaches stage 3 or 4, the cumulative heat exposure has been excessive and the vaccine must be discarded regardless of expiry date.

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.