The efficiency of cold chain system for oral polio vaccine as monitored by Vaccine Vial Monitor (VVM) depends on:
Vaccine Vial Monitor (VVM) - Heat sensitive label that indicates cumulative heat exposure over time. - Whether the OPV l can be used or not depends upon the irreversible colour changes in vaccine l monitor. - If color of inside square lighter than outside circle - We can use the vaccine
Change in the colour of vaccine
Temperature indicator of the system
Viral potency test
Change in colour of monitor
Storage of vaccines