The Vaccine Vial Monitor (VVM) on a vial of BCG shows the inner square slightly darker than the outer circle but has NOT reached the endpoint. What is the correct interpretation?
- A The vaccine has been exposed to excessive heat and must be discarded
- B The vaccine is at the discard point; do not use
- C The vaccine can still be used; VVM has not reached the discard point ✓
- D The VVM indicates the vaccine has been frozen; use the Shake Test
Correct answer: C. The vaccine can still be used; VVM has not reached the discard point
Explanation
A VVM progresses from light to dark as cumulative heat exposure increases. The discard point is reached when the inner square becomes AS dark as or DARKER than the outer circle. If the inner square is only slightly darker than its original colour but still lighter than the outer circle, the vaccine is still usable. The VVM detects heat damage, not freezing; the Shake Test is used for freeze-sensitive 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.