Cold chain
I. Define cold chain,
Is the system of storing and transportation of vaccines at recommended temperature from the point of manufacture to the point of user .
The cold chain consist of a series of links that are designated to keep vaccines within world health organization recommended temperature range from the point of manufacture to the point of administration
II. List the components of cold chain,
The cold chain has three main components each of which must combine to ensure safe vaccines, transport and storage these components includes
- Transport and storage component
- Trained personnel
- Efficient management procedures.
III. List equipments for cold chain
The following are the equipments of cold chain
- Vaccines carries
- Cold boxes
- Refrigerators
- Freezer room
- Refrigerated truck for transportation .
IV. Explain procedures for arranging of vaccines in the refrigerator
The following are the procedures for arranging of vaccines in the refrigerator
- Wherever possible, store vaccines and diluents in a refrigerator that is reserved for this purpose. If other heat sensitive supplies, such as drugs, ointments, sera and samples, have to be stored in the refrigerator, label them clearly and keep them completely separate from the vaccines and diluents.
- Always arrange vaccines and diluents so that air can circulate freely , this also makes it easier to handle the vaccines.
- If vaccines or diluents are supplied their original cartons, arrange the boxes so that there is at least a two centimeter spaces between stacks mark the cartons clearly and make sure the markings are visible when the door or lid is opened
- If vaccines or diluents are supplied as individual containers, use a plastic tray, plastic box or other arrangement store the vaccine in an orderly fashion.
- If diluents is packaged with the vaccines, store the complete packaged product in the refrigerator. If diluents are supplied separately from the vaccine, store them in the refrigerator. If there is adequate space. If there is adequate space move the diluents to the refrigerator at least 24 hours before they are needed so there re cooled.
- Space vaccines with VVMs that show the most heat exposure in a separate container in refrigerator clearly marked “Heat exposed vials use first” if there are other vaccines at the same type in the refrigerator the vaccines with the darkest square should always be used first even if the expire date is later than the vaccines with the lighter squares
- If a multi-dose vial policy is in place follow the instruction for handling opened multi-dose vials exactly as described in the national policy. If the opened multi-dose vial will be used for the next session, the vials must placed in a separate container in the refrigerator which is clearly marked “Opened vials use first”
V. List tools for maintain cold chain
The following are the tools for maintain cold chain
- Heat indicator tools
- Freeze indicator tools
- Vaccine volume calculator
- Vaccine vial monitor
VI. List factors affecting quality of vaccines
The following are the factors affecting quality of vaccines
- Factor associated with vaccines administration
- Factor associated with vaccine it self
- Factor associated with endogenous to the blind
- Previous exposure
- Passive protection
- Immune suppression
VII. List indication and contra-indication of vaccines
The following are the indications of vaccines
a) It is important for people of lighter risk of serious influenza complication who live for higher risk individual
b) Vaccines is most effective way to prevent infection and severe outcome caused by influenza viruses
The following are the contra-indication of vaccines
- Rare condition in recipients that increase risk for serious adverse reaction
- History of severe allergic reaction after dose of vaccine must be contra-indicated
VIII. Explain strategies for vaccines delivery
- To strengthen the delivery of self and effective vaccines
- To have adequate monitoring system supplies and performance
- To involve local government in planning
- To ensure polio free status is maintained
- To strengthen community surveillance
- To strengthen repotting system of all level