A Vaccine Vial Monitor (VVM) is a heat-sensitive and time-sensitive label affixed to a vaccine vial that indicates whether a vaccine can be used, or if it has been damaged through exposure to excessive heat over time.112 The label
consists of an inner square inside a coloured circle. The square will start off a lighter colour than the circle, but gradually darkens over time if the vaccine is exposed to heat. The vaccine can be considered safe
VVMs were first introduced in 1996, following almost 20 years of development. Today, almost all vaccines supplied through UN procurement agencies include a VVM. The VVM is useful for vaccine delivery in two very important capacities:
Interpreting a VVM Cumulative heat exposure VVM start colour
Discard point
VVM start colour of the square is never snow-white, but always has a bluish-grey tinge. From then on, until the temperature and/or duration of heat reaches a level known to degrade the vaccine beyond acceptable limits, the inner square remains a lighter colour than the outer circle colour.
Beyond discard point. Square colour is darker than colour of outer circle.
Do Not use this vaccine, inform your supervisor
Use this Vaccine
for use so long as the square remains a lighter shade than the outer circle. Once the square is the same shade, or a darker shade than the outer circle, the vaccine is no longer safe for use, and must be discarded.
Annex 1: Vaccine Vial Monitors (VVM)
Annex 1: Vaccine Vial Monitors (VVM)
(1) VVM give health workers the ability to visually and easily assess a vaccine’s appropriateness for use, without any detailed information on the vaccine’s cold chain or transport route. (2) The ability to assess heat exposure with a VVM helps prevent viable vaccines from being thrown away or wasted if the cold chain fails for short period of time at a service delivery point.
How does the VVM vary for different vaccines? Four categories of VVM identify the different levels of heat stability a vaccine presentation may fall under. Vaccines that prevent the same type
of disease but originate with different manufacturers, or have different presentations, may have different VVMs. The chart below illustrates the
different VVM categories and the length of time vaccines in each category can be exposed to levels of heat before reaching their discard point.
Table 1: VVM reaction rates by category of heat stability No. of days to end point at +37˚C
No. of days to end point at +25˚C
Time to end point at +5˚C
VVM 30: High Stability
30
193
> 4 years
VVM 14: Medium Stability
14
90
> 3 years
VVM 7: Moderate Stability
7
45
> 2 years
VVM 2: Least Stable
2
N/A*
225 days
Category (Vaccines)
* V VM (Arrhenius) reaction rates determined at two temperature points.
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