Cold Chain – An Overview
Cold Chain is a system of
transporting and storing
vaccines at recommended
temperature from the point of
manufacture to the point of
Essential Elements of Cold Chain
PERSONNEL to organize and
manage vaccine distribution
EQUIPMENT for storage and
transport of vaccines.
Maintenance of equipment
• 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 sensitive to heat
Vaccines sensitive to freezing
Ice lined refridgerators (ILRs)
•Capacity: 140 litres at PHC level(1200 vials)
•Ideal Temperature: +2 C to 8 C
(Effective with electricity supply of 8/24 hrs)
•Safe Storage: Always in the basket section
(Always T series, Hepatitis-B and Diluents)
(OPV/Measles/BCG may be kept below basket in case
space is not available)
•Thermometer: Place in the ILR-basket
Right way of keeping vaccines
• Keep all vaccines in baskets
• Place a thermometer in the
center of the ILR.
• Avoid placing vaccines at bottom
of ILR. (never diluents, freeze sensitive)
• Leave space between the
• Same vaccines in same area.
• Diluent / freeze sensitive/ Closer expiry date vaccines on top
• Heat sensitive / Further expiry date vaccines in the bottom of basket
Deep freezers (DF)
• Capacity: 140 litres at PHC level
• Ideal Temperature: -18 C to -20 C
(In case of power failure - maintain
temperature for 18-20 hrs)
• Ice Pack Freezing Capacity:
freezes 20 ice packs every 24 hours.
• Type: Insulated boxes of 5 litre capacity
• Usage: Stores & transports vaccine. Also stores
frozen Ice Packs
• Capacity: 1500 doses (mixed antigen) or 5000
doses (only OPV) with 24 ice packs.
• Holdover Time:3 days (Keep thermometer
• 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
• Type: Insulated boxes used for carrying small
quantities of vaccine.
• Capacity: 16-20 vials
• Holdover Time: Maintain +2 to+80 C for about
24 hours (one day)
• Ice packs: A maximum of 4 frozen packs
• Vaccine Layout: Keep vaccines in a plastic bag
(not in direct touch with the Ice packs)
• Do not fill 100%.
• Leave 10 mm room for
expansion as water freezes.
• Close the cap tightly
• Clean the outer surface dry
Ice Pack Freezing
• Ice Packs to be frozen ROCK Solid
• Freezing is faster & uniform if gap
/breathing space is left between ice packs
• Ice Packs are best frozen in Deep Freezers
• Condition before use
Preparing icepacks for use: Conditioning
A Conditioned ice-pack
•On the session day,
take the frozen ice-packs
you need from the
freezer and place on a
•Allow ice-packs to
sweat (droplets of water)
at room temperature
•Shake the ice pack to
listen to sound of water.
Maintenance of Equipment
• Defrosting/Cleaning: Ice deposit 5mm & over in
freezer or at the bottom of ILR results in rise in
temperature. Periodic defrosting & cleaning ensures
trouble free performance for a long period.
• Cold boxes/Vaccine Carriers: Cold box hinges, lid
knobs & chains are often damaged. Replace or repair
locally. Minor insulation casing cracks/gaps can also be
repaired with fresh PUF insulation
• Ice Packs: Fill clean water for freezing & leave 10mm
room for expansion as water freezes. Cap tightly to avoid
leakage. Keep pack clean & dry.
• 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) 16www.drjayeshpatidar.blogspot.in
• Monitor temperature twice daily.
• All vaccines at PHC are stored
between +2 to+8 C
Shake the control and test samples
• Hold the Control and the
Test sample together in
hand and vigorously shake
• Place both vials to rest on
a flat surface, side-by-side
observe them for 30
• Compare for rate of
Vaccine Vial Monitor
3 = bad:
4 = bad:
The central square is equal to, or
darker than the surrounding circle
1 = good:
2 = good:
The central square is lighter
than the surrounding circle
• T series, Hep B and diluents should never be frozen.
• BCG, OPV & Measles are sensitive to heat and light & lose
• Potency lost due to heat exposure does not change the
appearance of the vaccine.
• VVM is an effective tool in monitoring OPV potency.
• Damage to vaccine cannot be reversed by re-freezing.
• Discard frozen vaccine.