IMMUNIZATION METHODS
These are various means by which immunization services can get to the people. The common methods used for routine or supplementary immunization services are;
1. STATIC CENTERS
These are designed centers or areas in which the normal routine immunization services including health education and medical consultation services can be rendered by trained health personnel.
The static centers can be categorize into four (4) namely;
a. Hospital immunization center or unit
b. Comprehensive Health centers
c. Primary Health centers
d. School demonstration clinics
2. MOBILE UNITS
This refers to all hard to reach areas such as migrants, herdsmen and the fishermen settlements. The areas are so remote that the only possible way of reaching them is by foot, bicycles or in some cases by boats or motor – cycles.
3. NATIONAL IMMUNIZATION DAYS (NIDs), SIDs and LIDs:
This is the most efficient method of providing immunizations services to the people. NIDs/SIDs/LIDs are immensely undertaken in which health workers and volunteers go from house to house in the target areas to immunize children against e.g poliomyelitis and other childhood killer diseases. NIDs/SIDs/LIDs also provides vitamin A supplementation, which help in reducing childhood deat5hs resulting from common infectious diseases.
MANAGEMENT OF COLD CHAIN AND STORAGE SYSTEM
3.1 THE COLD CHAIN SYSTEM
Cold chain is a logistic system of keeping vaccines cold at a recommended temperature that will ensure their potency from the manufacturers end to the points at which they are administered to the recipients.
Cold chain is an important component of every immunization programme, which implies that careful attention has to be taken in transportation, storage and administration of vaccines to avoid loss of vaccine potency.
COLD CHAIN EQUIPMENTS
The cold chain equipment includes:
- Refrigerator
- Freezers
- Cold box
- Vaccine carrier
- Ice – pack
- Thermo flask
- Thermometer
Refrigerator
Refrigerator maintains a temperature range from 0o – 8oc. It keeps certain vaccines and diluents cold e.g Tetanus Toxoids (TT), Diphtheria Pertussis tetanus (DPT), and Hepatitis B (HBV) vaccines.
The refrigerator should be checked twice daily to ensure that it is in good working condition.
Freezer
The freezer work at a temperature below freezing points that is temperature range between -15o to -25oc. Vaccines usually stored in freezer include oral polio vaccine (OPV), measles vaccine and yellow fever (YF).
The freezer is also used in making ice – packs and should be checked twice daily to ensure that it is in a good working condition.
Cold box
The cold box is used to store large quantities of vaccines from cold store to health centre. Cold box keeps vaccines cold for up to one week. It should be handled with care especially when there are vaccines inside.
Vaccine carrier
Is small equipment which is used in transporting small amount of vaccines to outreach unit. It is portable and can easily be carried by an individual or on bicycles. It can only preserve vaccines for a maximum of one day.
Ice – pack
Is a plastic bottle which contains solid ice that is formed in the freezer. It keeps the vaccines cold within the period of immunization exercise in the same day.
Thermo flask
This is mobile cold chain equipment that can be used especially when the vaccination trips involved house -to – house such as in the national immunization days (NIDs). It carries very little amount of vaccines and can only keep vaccines cold for a maximum of six (6) hours
HOW TO MAINTAIN COLD CHAIN AND STORAGE SYSTEM
Vaccine storage
This means all the steps taken to protect vaccines and to ensure that they are in good working conditions as well as keeping to the appropriate temperature in their vaccine storage equipment. The steps that must be considered are as follows:
i. Store each vaccine at its storage temperature.
ii. Record temperature twice daily i.e. morning and evening.
iii. Insert cold chain monitoring chart which is designed to last for a whole year and in which provisions have been made for every day and monthly charting.
iv. Insert functional thermometer which will enhance effective monitoring of temperature. The thermometer is calibrated to read either positive when it is refrigerated and negative when it is frozen. The thermometer must be kept whenever vaccines are stored.
v. Vaccines should not be compacted in a shelve or compartments, for instance, vaccines that are to be kept frozen should be put in freezers, while the ones that are not to be frozen should be put in refrigerators.
vi. Tetanus Toxoids (TT), DPT and Hepatitis B should be stored at a temperature of +20 to +40c and even up to +80c in refrigerators.
vii. Oral polio vaccines (OPV), measles vaccines, yellow fever vaccines (YFV) and BCG vaccines should be stored at -15o to -250c.
viii. All received and stored vaccines should be recorded accordingly.
ix. Food items should not be stored in the same refrigerator with vaccines.
x. Vaccines should not be stored in refrigerator’s door.
Maintenance of cold chain system from port to zonal stores
1- Ensure
2- Vaccines are transported in cold boxes.
3- Vehicle for transportation must be reliable.
4- If it breaks down, keep vaccine in a refrigerator to keep the vaccine cold and maintain its potency.
5- Ensure that the officer handling the vaccines at the point in time is responsible, dedicated and knowledgeable about the consignment.
At the zonal health office, health clinic and health centres
1- Keep vaccines in the refrigerator at the store; check the refrigerator two times daily in a week, day and once daily on the weekend.
2- Defreeze once a week.
3- Request only enough vaccine to do your work.
4- Do not keep extra vaccines that cannot be used.
5- Pack cold boxes properly and protect them from heat which vaccines are inside.
6- Keep the ice box door shut except when taking the temperature.
7- Do not allow anyone to use the vaccine refrigerator to store food or drinks
3.3 HOW TO ESTIMATE AND REQUEST FOR VACCINE AND OTHER COLD CHAIN EQUIPMENTS
ESTIMATING TARGET POPULATION
The target population for routine immunization
• Infant under one year (0-11mth) = 4% of the total population.
• Women of child bearing age (15-49yrs) =22% of the total population.
Population figures for settlements should be obtained from the projected census population from the national population commission.