Tresivac Caution For Usage

The Vaccine Vial Monitor (VVM) (Optional): Vaccine Vial Monitors (VVM): Use: Square is lighter than outer circle.
Discard Point: The colour of the inner square of the VVM starts with a shade that is lighter than the outer circle and continues to darken with time and/or exposure to heat.
Do not use: Square matches outer circle; Square is darker than outer circle.
Discard Point: Once a vaccine has reached or exceeded the discard point, the colour of the inner square will be the same colour or darker than the outer circle.
Inform the supervisor.
Cumulative heat exposure over time.
Vaccine Vial Monitors (VVMs) are on the cap of Measles, Mumps and Rubella Vaccine Live Attenuated supplied through Serum Institute of India Pvt. Ltd. This is a time-temperature sensitive dot that provides an indications of the cumulative heat to which the vial has been exposed. It warns the end user when exposure to heat is likely to have degraded the vaccine beyond an acceptable level.
The interpretation of the VVM is simple. Focus on the central square. Its colour will change progressively. As long as the colour of this square is lighter than the colour of the outer circle, then the vaccine can be used. As soon as the colour of the central square is the same colour as the outer circle or of a darker colour than the outer circle, then the vial should be discarded.