Neobook — clinical reference

Maintaining the cold chain means keeping vaccines at the right temperature throughout distribution, storage and use. The cold chain can be maintained by:

Never exposing vaccines to heat or freezing conditions, especially during transportation from one point to another
Always using a cold box to keep the vaccines cold during transport and immunisation
All vaccines should be kept in a refrigerator at a temperature of 2–8°C
Open vials of OPV should not be kept in the freezer or be allowed to freeze again. However, closed vials of OPV may be thawed and frozen, multiple times and should ideally be stored at -20°C
Use continuous temperature monitoring device e.g. fridge-tag for all vaccines (Min-max thermometer/dial thermometer not recommended)
Ensure that Hexavalent (DTaP-IPV-HB-Hib), HPV, PCV, RV, Tdap, and TT vaccines do not come into contact with the refrigerator's evaporator at the back/sides, as they are sensitive to freezing. Do not freeze these vaccines, and do not use any vaccines that have been frozen. If there is a suspicion of freezing, conduct the shake test to determine if the vaccines have frozen and need to be discarded
Monitor and record fridge temperature twice daily
Leave space between each tray to allow cold air to circulate
Do not keep food in the same fridge as the vaccines
If possible do not keep other medications e.g. insulin etc. in the vaccine fridge
Do not keep blood and other specimens in the vaccine fridge

Correct packing of the cold box

Conditioned ice packs (the ice should rattle inside the pack) are placed on the bottom, at the sides and on top
If there are not enough ice packs, place available ice packs at the sides and on top of the vaccines
Tdap, TT, HPV, PCV, RV and Hexavalent vaccines must not be allowed to freeze
Keep measles/rubella and polio vaccines very cold - place on bottom of the cold box, closest to the ice packs
BCG can be placed anywhere in the box
Keep the lid firmly closed and the box out of the sun
Keep a continuous temperature monitoring device in the cold box with the vaccines and the temperature at 2–8°C
Live attenuated vaccines (BCG, OPV, measles/rubella) are very sensitive to heat, sunlight, and skin antiseptics

How to pack your fridge correctly

Vaccines should be stored in a purpose-built vaccine fridge. However, if unavailable store the vaccines in a domestic fridge, as follows:
- Top shelf: measles and polio vaccines in the coldest part
- Middle shelf: BCG, Tdap, Hexavalent (DTaP-IPV-HB-Hib), HPV, RV, PCV and TT vaccines (do not freeze) with sufficient diluent for the BCG and measles/rubella for 2 days
- Do not let Tdap, Hexavalent (DTaP-IPV-HB-Hib) HPV, RV, PCV and TT vaccines touch the evaporator plate at the back/side of the fridge as they are destroyed by freezing
- Do not keep vaccines in the fridge door
- Store the same kind of vaccines together in one tray
- Leave about 2 cm space between each tray to allow the cold air to move around
- Saltwater-filled bottles placed at the bottom of the fridge can prolong the holdover time, enabling the fridge to return promptly to its set temperature after being opened

Do not keep food in the same fridge as the vaccines to avoid unnecessary opening of the door.

There should be a contingency plan written and posted on every vaccine fridge of what to do in the event of a power failure
Monitor and record temperature twice daily

CAUTION

Do not use vaccines that have expired, reached discard point as indicated by the VVM, or where the cold chain has been compromised.
Keep the fridge temperature between 2–8°C.

Note:
All vaccines with a “T” in the name are sensitive to freezing: TT, Tdap, HexavalenT, RoTavirus, HepaTiTis B and even diluenTs. Diluents (for measles/rubella and BCG) should never be frozen.

Click here to access the pdf.

Standard Treatment Guidelines and Essential Medicines List for South Africa, Primary Healthcare, 2020-2024_Version 1.1_6 December 2024

Chapter 13: Immunisation_13.4 The Cold Chain