Title: Safety of the cold chain
Course: Immunization - Ethiopia (Full)

Safety of the cold chain

If vaccines are spoiled by incorrect storage conditions, they will not be effective in preventing the associated disease, and they could also cause adverse reactions. This is also true for the diluents (ampoules of special liquid) used to reconstitute the freeze-dried (powder) BCG and measles vaccines before use. Each of these vaccines has its own specific diluent, which cannot be used for another vaccine. Diluents can be stored at room temperature if there is no room for them in the refrigerator, but before use they must be completely chilled to between +2^oC and +8^oC, so they reach the same temperature as the vaccine they are being mixed with.

Which vaccines and diluents available for routine use in the EPI in Ethiopia should not be frozen? What action should you take if freezing occurs?

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Pentavalent vaccine, PCV10, TT and OPV should not be frozen. Also, the diluents for reconstituting BCG and measles vaccines should not be frozen. If any of these vaccines or diluents becomes frozen, they are no longer effective and should be discarded.

Which vaccines can be frozen (under exceptional circumstances) for temporary storage?

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The only EPI vaccines in Ethiopia that can be frozen are the freeze-dried powder vaccines (BCG and measles) before reconstitution. Normally, all vaccines should be stored at between +2ºC and +8 ºC in the main (chilled) compartment of the vaccine refrigerator.