DEFINITION
Cold Chain is a system of transporting vaccine at recommended temperature from
the point of manufacturing to the point of use
ESSENTIALS OF COLD CHAIN
• Equipment
• Power
• Maintenance of Equipment
• Monitoring
EQUIPMENT - ELECTRICAL
• Walk-in-Freezer ( WIF ):. Stores bulk quantity of OPV/Measles & freezes Ice Packs at -20°C.
• Walk-in-Cooler ( WIC ): storage of bulk vaccine at State & Regional stores. Storage Temp. is + 2°C to + 8°C
• Deep Freezers ( DF )
• Ice Lined Refrigerators ( ILR )
In general,
• All Vaccines tend to lose potency on exposure to heat above +80 C
• Some Vaccines lose potency when exposed to freezing temperatures
• The damage is irreversible
Vaccines vulnerable to heat
BCG
OPV
Measles
HepB
DPT
DT
TT
Vaccines vulnerable to Freezing
Hep- B
DPT
DT
TT
Ice cream principle
Colder the better does not hold good for all vaccines
Ice lined refrigerators (ILRs)
• Capacity: 300 & 140 ltrs
• Ideal Temperature: +2°C to 8°C
• Vaccine Storage capacity:
– 300 ltrs stores 60000 doses of mixed antigen
– 140 ltrs stores 25000 doses of mixed antigen
• Safe Storage: Always in the basket section
Deep freezers (DF)
• Capacity: 300 & 140 ltrs
• Ideal Temperature: -18°C to -20°C
• Ice Pack Freezing Capacity:
300 ltrs freezes 40 packs every 24 hours.
140 ltrs freezes 25 packs every 24 hours.
Equipment – non electrical
• Cold Boxes: Placed at State/Region/ DHQ/PHC
• Vaccine Carrier: Placed at DHQ/PHC & sub centres.
• Ice Packs: Placed at State WIF /DHQ/PHC & sub centres.
Cold Boxes
• Type: Insulated boxes of 20 ltrs & 5 ltr capacity
• Usage: Stores & Transports vaccine. Also stores frozen Ice Packs
• Vaccine Layout: Direct contact of frozen Ice packs spoil the vaccine. Give carton spacers/surround vaccine by OPV vials.
• Label Protection: Place vaccine in cartons or polythene bags.
Vaccine Carrier
• Type: Insulated boxes used for carrying small quantities of vaccine.
• Capacity: 16-20 vials
• Ice packs: A maximum of 4 frozen packs
• Vaccine Layout: Keep vaccine clear off direct touch with the Ice Packs
Ice Packs
Water Fill: Do not fill 100%. Leave 10mm room for expansion as water freezes. Condition before use. Do fill the Ice packs up to the marked line.
• Usage: Lowers Temp range for safe vaccine storage. Placed in side lining of ILR to improve & maintain holdover time during electrical failure.
• Best Frozen: In WIF, DF & Ice factories.
Supplies
• Base supplies as per demand & utilization.
• Supply to Districts/PHC after assessing monthly usage & balance stock in hand.
• Districts need to maintain some buffer stock for any unforeseen demand.
• Transport the vaccine in strict cold chain.
• Rotate stocks – “vaccine in first out first”
• Check early expiry date vials & use first.
Vaccine Distribution
• Follow first-in-first - out rule (FIFO)
• Also: first to expire - first out. (FEFO)
• Vaccines are not stored at the sub-centre level and must be supplied on the day of use
• Note manufacturer, batch no., VVM status
• Use VVM stage-II vaccine near the cold chain point (do not distribute to remote areas)
Potency
• T series, Hep B and Hib and diluents should never be frozen.
• BCG, OPV & Measles (light) are sensitive to heat & lose potency fast.
• Potency lost due to heat exposure does not change the appearance of the vaccine.
• VVM is an effective tool in monitoring OPV (and measles) potency.
• Damage to vaccine cannot be reversed by re-freezing.
• Discard frozen vaccine.
Conditioning
• On the session day, take the frozen ice-packs you need from the freezer and place on a table
• Allow ice-packs to sweat at room temperature for some time
• Shake the ice pack to listen to melted for water.
Shake test
• Hold the Control and the Test sample together in hand and vigorously shake the samples
• Place both vials to rest on a flat surface, side-by-side observe them for 30 minutes.
• Compare for rate of sedimentation
