Immunization Handbook for Medical Officers - Nccvmtc.org

measure exposure to freezing that contributes to the
degradation of freeze-sensitive vaccines.
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2
Usable Stages
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Reading the Stages of the VVM
1. The inner square is lighter than the outer
circle. If the expiry date has not been
passed : USE the vaccine
2. The inner square is still lighter than the
outer circle. If the expiry date has not been
passed: USE the vaccine
Discard Point:
3. The colour of the inner square matches that
of the outer circle: DO NOT use the
vaccine
Un-usable Stages
Figure 4.1: Different stages of the VVM
Beyond the Discard Point:
4. The colour of the inner square is darker
than the outer circle: DO NOT use the
vaccine
Correct Storage and Use of Diluents
Only use the diluents supplied and packaged by the manufacturer with
the vaccine, since the diluent is specifically designed for the needs of
that vaccine, with respect to volume, PH level and chemical properties.
Store the diluents, between +2° to +8°C in the ILR. If there are constraints of
space, the store diluents outside the cold chain. However, remember to cool
diluents for at least 24 hours before use to ensure that vaccines and diluents
are at +2° to +8°C when being reconstituted. Otherwise, it can lead to thermal
shock i.e. the death of some or all the essential live organisms in the vaccine.
Store the diluents and droppers with the vaccines in the vaccine carrier during
transportation. Diluents should not come in direct contact with the ice pack.
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