PHS419 Immunology, Immunization and Cold Chain Treatment PDF

# PHS419-IMMUNOLOGY, IMMUNIZATION AND COLD CHAIN TREATMENT ## PHS419-IMMUNOLOGY, IMMUNIZATION AND COLD CHAIN TREATMENT 2credits - Elective **By** Dr. Yusuf F. Issa, MBBS, MPH, FCAI, FWACP, FRSPH, Cert Proj. Mgt. Department of Public Health, Faculty of Pure and Applied Sciences, Kwara State University, Malete # Vaccination, Immunization and Cold Chain System ## Vaccination, Immunization and Cold Chain System # Vaccination, Immunization and Immunizable Diseases ## Vaccination, Immunization and Immunizable Diseases - Vaccination: Process of inoculating vaccine/antigen. - Immunization: Process of inducing immune response humoral/CMI. (watch video on differences between vaccination and immunization) - Seroconversion: Change from antibody negative state to antibody positive state. - Seroprotection: The state of protection (from disease) due to the presence of humoral immunity of antibody. - Antibody titre: The reciprocal of the highest serum dilution at which antibody has been detected. - Geometric mean titre (GMT): The mean antibody titre in a group of individuals. - Selection of vaccines: Criteria for selection of vaccine are necessity, safety and efficacy - Childhood immunizable diseases include-Tuberculosis, Poliomyelitis, Diphtheria, Tetanus, Pertusis, Measles, Yellow Fever # Types of immunizing agents ## Types of immunizing agents Type of antigen | Examples ------- | -------- Live bacteria, attenuated | BCG, Ty 21 a. Live virus attenuated | OPV, MMR Varicella Killed bacteria | Pertussis, S. typhi Killed virus | IPV, Rabies, HAV Toxoids | DT, TT Capsular Polysaccharide | Typhoid Vi. PCV 10, Hib, Meningoccoccal Viral subunit | Hbs Ag Bacterial subunit | Acellular pertussis Recombinant DNA | Hep B # Types of immunizing agents (2) ## Types of immunizing agents (2) ### Differences between live and killed vaccines | Attenuated | Killed | | ------ | -------- | | Vaccine dose | Low | High | | Immunity | Long | Short | | Boosters | Not usual | Frequent boosters | | Revaccination | Possible | None | | Latency | Possible | None | | Oncogenecity | ? | None | # Vaccine Trials ## Vaccine Trials - Every vaccine has to undergo the three basic trials before it is licensed for use. - Phase 1 Trial: (Human volunteers, for tolerance, safety) - Phase 11 Trial: (Human volunteers, for immune response, safety) - Phase 111 Trial (for field efficacy safety) # Vaccines Efficacy ## Vaccines Efficacy - Prolonged exposure of vaccines to adverse temperatures affects its potency - For vaccines to be effective, the altered live organism/product must retain their ability to induce a protective immune response - Factors affecting potency of vaccines include: 1- Temperature, 2- Timing, 3- Immune status, 4- Age of recipient, 5- Technique of administration, 6- Route of administration - Innovations to ensure vaccine efficacy: - Vaccine Vial Monitor (VVM) - a special device placed on each vaccine vial to monitor heat exposure over time. It monitors individual vials (Watch Video on VVM) - Cold Chain Monitor (CCM) - monitor the consignment as opposed to VVM - Satellite Cold Storage, Walk In Cold Rooms (WIC) - Solar refrigerator, Solar Direct Drive Refrigerator (SDDR) # National Routine Immunization Schedule ## National Routine Immunization Schedule ### Age | Vaccines | Route ------- | -------- | -------- Birth | BCG, OPV-0, Hep B | Intradermal, Oral, Intramuscular 6 weeks | Penta 1, OPV1, PCV1 | Intramuscular, Oral, Intramuscular 10 weeks | Penta 2, OPV2, PCV2 | Intramuscular, Oral, Intramuscular 14 weeks | Penta 3, OPV3, PCV3, IPV | Intramuscular, Oral, Intramuscular 6 months | Vitamin A | Oral 9 months | Measles, Yellow Fever, Meningococcal A, Vitamin A | Subcutaneous/Intramuscular/Oral 12 months | Vitamin A 200,000 I.U. | Oral 15 months | Measles 2nd Dose (MCV2) | Subcutaneous NB. See the full current RI schedule, August 2019 ## National Routine Immunization Schedule For Pregnant women or Women of Child Bearing Age (WCBA): - TT 1st dose given at first contact - TT 2nd dose given 4 weeks after TT1 - TT 3rd dose given 6 months after TT2 - TT 4th dose given 1 year after TT3 - TT 5th dose given 1 year after TT4 NB. See the current RI schedule, August 2019 # Vaccine Cold Chain System ## Vaccine Cold Chain System - The cold chain is a system of transporting and storing vaccine at recommended temperatures from the manufacturer to the point of use. (Watch Video) - It consists of a series of transportation links during which adequate refrigeration is required to maintain vaccine potency. - Importance: Prevention of risk of vaccine failure during its transport from the manufacturer to the mother/child receiving it. - Most vaccine are sensitive to heat. - Vaccine most sensitive to heat is Polio and least sensitive to heat is Tetanus. - Temperature at which most of the vaccines will retain their potency +2° C- +8° С. - Ideal temperature at which Polio and measles vaccine should be kept is subzero temperatures # Vaccine Cold Chain in Nigeria ## Vaccine Cold Chain in Nigeria The Nigerian vaccine cold chain | National store | |---| | 1 | | Zonal store | |---| | 6 | | State store | |---| | 37 | | Satellite stores | |---| | LGA store | |---| | 774 | | Health facility | |---| | ~25,000 | *Weekly dashboard feedbacks and monthly newsletter* *Weekly stock data is aggregated* # Vaccine Cold Chain System (2) ## Vaccine Cold Chain System (2) ### Essential Elements of a Cold Chain - People to organize and manage vaccine distribution. - Equipment to store and transport the vaccine. - Transport facilities. ### Activities to be carried out to manage the Cold Chain System - Enumerate the eligibles - Obtain vaccines. - Maintain equipment - Maintain vaccines - Monitor cold chain. # Vaccine Cold Chain System (3) ## Vaccine Cold Chain System (3) ### Enumerate the Eligibles - House-to-house enumeration of pregnant women and infants. - Regular updating done by the MPWs during routine visits (multipurpose workers). - Pregnant women= Population x BR= 5% of total population - Infants = Population x BR x (1-IMR)=4% of total population ### Obtain Vaccines - This involves - Calculating vaccine requirement. # Vaccine Cold Chain System (4) ## Vaccine Cold Chain System (4) ### Estimating Vaccine requirement. - This is done by multiplying axbx c x d and dividing by 'e' - a = Total no of pregnant women/infants in the area - b = Proposed coverage - c = No. of doses of vaccine to be given (including boosters) - d = WMF (Wastage multiplication factor) - e = Divided by no. of doses per vial - Wastage multiplication factor for BCG/Measles is 1.5 and for DPT/OPV is 1.33 ### Shake Test - DPT, DT, TT Vaccines if frozen on shaking will form # Vaccine Cold Chain System (5) ## Vaccine Cold Chain System (5) ### Monitor cold chain - This is done by (a) monitoring supplies (b) maintaining temperature during transport (c) storage temperatures (d) potency tests. - Indicator vaccine for potency testing is OPV (since it is the most heat sensitive) ### Remember - Do not stock vaccines for more than 3 months at the district store. - Do not stock for more than 1 month at the PHC. - Do not stock vaccines at the sub-centre. - All vaccines are safe at temperature of 2-8°C for 4 months at least. - Polio and measles vaccines kept in a freezer for long-term storage - Do not freeze DPT, DT, TT. - Transport vaccines in cold boxes/vaccine carriers. - Check icepacks. - Travel by the shortest route - Vaccine Vial Monitor -Currently VVM is available for temperature monitoring # Cold Chain Equipment ## Cold Chain Equipment ### Maintain Equipment - Equipment for vaccine storage in cold chain are: - (a) Vaccine carriers (b) Day carriers (c) Thermocol box (d) - Refrigerator (e) Iced-lined Refridgerator (ILR) (f) Deep freezer - (g) Cold box. - **Vaccine carriers:** They are equipments used to transport small quantities of the vaccine from PHCs to subcentres. The efficiency of cold chain maintenance depends on the thickness and quality of the insulation material used. Icepacks should be fully frozen and the lid of the carrier tightly shut. A vaccine carrier with 4 fully frozen icepacks can store the vaccines efficiently for 2 days. - **Day carriers:** Small vaccine carriers with 2 icepacks one each at the top and bottom. Keeps vaccine safe for 6 to 8 hours. - **Thermocole boxes:** Less durable and cheap. Icepacked in a plastic cover and kept at the bottom and top of vaccine vials, but not in direct contact. # Cold Chain Equipment (2) ## Cold Chain Equipment (2) - **Refrigerators:** Every PHC should have at least one ILR- top opening refrigerator. - **Icelined refrigerators:** Top opening refrigerators. Acts as a buffer in case of power failure. - ILRs keep the vaccines safe even without electrical supply of 8 hours out of 24 hours - Bottom of the ILRs is the coolest place. DPT, DT,TT should not be kept at the bottom. - Temperature recordings inside the ILR should be done twice daily by the health workers. ### Distribution of vaccines - From the district store to the PHC and from the PHC to the sub-centre. # Storage Temperature Requirements for Vaccines ## Storage Temperature Requirements for Vaccines - Vaccines are sensitive biological products - Some vaccines are sensitive to freezing, some vaccines are sensitive to light and all vaccines are sensitive to heat. - Vaccine potency is the ability of the vaccine to adequately protect the vaccinated client. - Potency can be diminished when the vaccine is exposed to inappropriate temperatures. - Once lost, vaccine potency cannot be regained. To maintain quality, vaccines must be protected from extreme temperatures. - Vaccine quality is maintained using a cold chain that meets specific temperature requirements. - At the health facility level, all vaccines should be kept within +2 °C to +8 °C. **Note:** - Diluents should never be frozen. - If diluents are packaged with the vaccine, the combined product should be stored at +2 °C to +8 °C. # Vaccine Sensitivity to Heat and Freezing ## Vaccine Sensitivity to Heat and Freezing Table below shows the relative heat sensitivity of vaccines. - These vaccines are grouped into six categories. Within each of these six categories, the vaccines are arranged in alphabetical order, not in order of sensitivity to heat within the group. The most heat sensitive vaccines are in Group A and the least heat sensitive are in Group F. | Most sensitive | | | | | Least sensitive | | ---------------- | - | - | - | - | ---------------- | | **GroupA** | **GroupB** | **GroupC** | **GroupD** | **GroupE** | **GroupF** | | Oral poliovirus (OPV) | Influenza | Inactivated poliovirus (IPV) (Freeze-dried) Measles Measles-Rubella Measles-Mumps-Rubella (freeze-dried) | Cholera DPT-HepB-Hib (pentavalent) Hib (liquid) Rotavirus (liquid and freeze-dried) Yellow fever (freeze-dried) | Bacillus Calmette-Guerin (BCG) Human papillomavirus (HPV) Tetanus, TD, Td | Hepatitis B Hib (freeze-dried) Meningococcal A Pneumococcal conjugate (PCV) | # Vaccine Sensitivity to Light ## Vaccine Sensitivity to Light - Some vaccines are very sensitive to light and loose potency when exposed to a source of light. - Such vaccines should always be protected against sunlight or to artificial light sources such as fluorescent light (energy savers or fluorescent tubes). Exposure to these light sources should be minimized. - Vaccines that are sensitive to light include BCG, Measles, Measles-Rubella, Measles-Mumps-Rubella and Rubella. - These vaccines are often supplied in dark glass vials that give them some protection from light damage. - It is advisable to keep them in their secondary packaging for as long as possible to protect them during storage and transportation - Light sensitive vaccines in dark glass ampoule/vial: # Freeze Sensitive Vaccines ## Freeze Sensitive Vaccines - Vaccines that are sensitive to freezing that should be protected from sub-zero temperatures are: (DO NOT FREEZE THESE VACCINES!) - Cholera vaccine - DPT-HepB-Hib (Pentavalent) vaccine - Hepatitis B (HepB) vaccine - Hib (Liquid) vaccine - Human Papilloma virus (HPV) vaccine - Inactivated Polio Virus (IPV) vaccine - Influenza vaccine - Pneumococcal Conjugate (PCV) vaccine - Tetanus-diphtheria (Td) vaccine - Meningococcal Conjugate (MenA) vaccine - Rotavirus vaccine Note that the heat stability information shown for freeze-dried vaccines applies only to unopened vials; most freeze-dried vaccines rapidly lose potency after reconstitution. In addition, it is important to keep opened multi-dose vaccine vials that do not contain preservative, whether powdered or liquid, cooled at temperatures between +2 °C and +8 °C during the immunization session. They should however be discarded at the end of the immunization session or after six hours of opening, whichever comes first (Read Vaccine MDVP). # VACCINE MULTI-DOSE VIAL POLICY (MDVP) ## VACCINE MULTI-DOSE VIAL POLICY (MDVP) - Summary of Nigeria National Multi-dose Vial Policy (MDVP), 2009 - Open multi-dose vial policy states that liquid vaccines opened for an immunization session, can be used within 4 weeks in subsequent sessions provided that all the following conditions are met: - The expiry date is still within limits. - The vaccines are stored under appropriate cold chain conditions. - The VVM if attached has not reached discard point. - The septum is not submerged in water - Aseptic technique has been used - These apply to vaccine vials used in outreach and mass campaigns provided that standard handling procedures are followed. - Vaccine vials may be discarded immediately if: - Sterile procedures have not been fully observed. - Contamination of the opened vial is suspected. Evidence of contamination is change in appearance, visible and floating particles. - Reconstituted freeze-dried vaccines should be discarded at the end of 6 hours or at the end of the immunization session or whichever comes first. - If ALL of the criteria cited above are met the vaccine vial may be kept and used for up to 28 days after opening, or until all the doses are administered, whichever comes first # Temperature Monitoring ## Temperature Monitoring - It is essential to monitor and record the temperature of vaccines throughout the supply chain. - This is the only way to prove that vaccines have been kept at the right temperature during storage and transport. - Temperature monitoring also shows up any problems with equipment and procedures - Most health facilities are generally equipped with one or two vaccine refrigerators, cold boxes and vaccine carriers. - There available devices to monitor heat exposure of vaccines as well as the temperature of cold chain equipment (CCE) - Vaccine Vial Monitor (VVM) is used to monitor heat exposure of vaccines - There are series of devices which are used to monitor the temperature in Cold Chain Equipment which include - 1. Temperature Loggers - 2. Fridge Tags - 5. Stem thermometers - 4. Integrated digital thermometers - 3. Freeze Tags - 6. Dial thermometers # Vaccine Vial Monitors (VVMs) ## Vaccine Vial Monitors (VVMs) - Vaccine Vial Monitors (VVMs) are the only temperature monitoring devices that routinely accompany vaccines throughout the entire supply chain. - A VVM is a chemical indicator label attached to the vaccine container (vial and ampoule) by the vaccine manufacturer. - As the container moves through the supply chain, the VVM records its cumulative heat exposure through a gradual change in colour (see Figure below). - If the colour of the inner square is the same colour or darker than the outer circle, the vaccine has been exposed to too much heat and should be discarded. - The main purpose of VVMs is to ensure that heat-damaged vaccines are not administered. - The VVM status is also used to decide which vaccines can safely be kept after a cold chain break occurs thus minimizing unnecessary vaccine wastage. - The VVM status helps the user decide which vaccine should be used first. A batch of vaccine showing significant heat exposure should be distributed and used before a batch that shows lower heat exposure, even if its expiry date is longer # Location of VVMs ## Location of VVMs - There are two different locations for VVMs and each is associated with specific guidance for handling opened multi-dose vials of vaccine: - 1. Where the VVM is on the label of the vaccine, the vaccine vial, once opened, can be kept for subsequent immunization sessions up to 28 days, regardless of the formulation of the product (liquid or freeze-dried). - 2. Where the VVM is attached in a location other than on the label (e.g., cap or neck of ampoule), the vaccine vial, once opened, must be discarded at the end of the immunization session or within six hours of opening, whichever comes first. - Location of VVMs on ampoules and vials: # Stages of VVM ## Stages of VVM - The vaccinator must also check the VVM before the vaccine is opened to see whether the vaccine has been damaged by heat. - Only use the vial if the expiry date has not passed, and if the inner square of the VVM is lighter in colour than the outside circle. The four (4)VVM ### Description of VVM appearance | The Vaccine Vial Monitor says... ------- | -------- Inner square lighter than outer circle. If the expiry date has not passed: USE the vaccine. | If the expiry date is not passed, USE the vaccine. At a later time, inner square still lighter than outer circle. If the expiry date has not passed: USE the vaccine Discard Point: Inner square matches colour of outer circle: DO NOT use the vaccine. Beyond the discard point: Inner square darker than outer ring: DO NOT use the vaccine. | USE the vaccine FIRST DO NOT USE the vaccine DO NOT USE the vaccine - VVMs do not measure exposure to freezing temperatures. - If the vaccine is freeze-sensitive and freezing is suspected, then the Shake Test must be conducted (watch video on how to conduct Shake Test) # Shake Test ## Shake Test - The Shake Test is used to check whether freeze-sensitive vaccines have been damaged by exposure to temperatures below 0 °C. (Watch Video) - After it has thawed, a vial of vaccine that has been frozen no longer has the appearance of a cloudy liquid, but tends to form flakes that settle at the bottom of the vial. - The Shake Test requires two vials of the same vaccine from the same manufacturer and with the same batch number. - One of these is a vial that you suspect has been frozen and the other is a vial that you have deliberately frozen solid overnight. - Allow the frozen test vial to melt completely, shake the two vials in the same hand, place them side-by-side and watch the contents settle. - If the suspect vial settles at the same speed or faster as the frozen vial you know that it has been frozen. If it settles more slowly, it has not been frozen. ### When is the Shake Test needed? - If a freeze indicator is activated, or temperature recordings show negative temperatures, freeze-sensitive vaccines may have been damaged. - If this occurs, the health worker must carry out the Shake Test on a sample of the suspected vaccine # How is the Shake Test done? ## How is the Shake Test done? - The Shake Test has a protocol which must not be altered and there is only one correct way to conduct a Shake Test. - The test procedure should be repeated with all suspect batches. - In the case of international arrivals, the shake test should be conducted on a random sample of vaccine. - However, if there is more than one lot in the shipment, the random sample must include a vial taken from each and every lot. (Watch video of how to conduct Shake Test) ### Procedure: - Take a vial of vaccine of the same type and batch number as the vaccine you want to test, and made by the same manufacturer. - Clearly mark the vial as "FROZEN." - Freeze the vial in a freezer or the freezing compartment of a refrigerator until the contents are completely solid. - Let it thaw. Do NOT heat it! - Take your "TEST" vial from the batch that you suspect has been frozen. - Hold the "FROZEN" vial and the "TEST" vial together in one hand. # How is the Shake Test done? contd. ## How is the Shake Test done? contd. ### Procedure: - Shake both vials vigorously for 10-15 seconds. - Place both vials on a flat surface side-by-side and start continuous observation of the vials until the test is finished - If the vials have large labels that conceal the vial contents, turn both vials upside down and observe sedimentation in the neck of the vial - Use an adequate source of light to compare the sedimentation rates between ! Compare the deliberately frozen vial next to the suspect vial # Recommended Temperatures for Vaccine Storage ## Recommended Temperatures for Vaccine Storage | Vaccine Storage Level | National/ Central Store | State / Regional Store | LGA /District Store | During Transportation | | ------- | -------- | -------- | -------- | -------- | | Maximum Storage Time | 8 to 12 months | Up to 3 months | Up to 1 month | 1 week | | BCG. OPV and Yellow Fever | -15°c to -25°c | | +2°c to +8°c | | | DPT. Td and HBV | | +2°c to + 8°c | | | # Temperature Monitoring Devices ## Temperature Monitoring Devices - Example of Temperature Loggers - Fridge Tag with USB - Freeze Tag - Dial and Stem - Thermometers

PHS419 Immunology, Immunization and Cold Chain Treatment PDF

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