Epi seminar

Expanded programme on immunisation (EPI)

Abdirisak Mohamed

IMMUNIZATION•Immunization is defined as the procedure by which the body is prepared to fight against a specific disease.

•Immunization is of two types:1. Passive immunization2. Active immunization.

� PASSIVE IMMUNIZATIONPassive immunization or immunity is produced without challenging the immune system of the body.

done by administration of serum or gamma globulins from a person who is already immunized (affected by the disease) to a non-immune person.

Passive immunization is acquired either naturally or artificially.

It is developed by injecting previously prepared antibodies using serum from humans or animals.

This type of immunity is useful for providing immediate protection against acute infections like tetanus, measles, etc.

ACTIVE IMMUNIZATION

Active immunization or immunity is acquired by activating immune system of the body.

Body develops resistance against disease by producing antibodies following the exposure to antigens.

Active immunity is acquire

NaturallyArtificially

Active Natural ImmunizationNaturally acquired active immunity involves activation of immune system in the body to produce antibodies against microorganism.

It is achieved in both clinical and subclinical infections

Active Artificial Immunization

It is achieved by the administration of vaccines or toxoids.

Herd Immunity• It is a type of immunity that occurs when the vaccination of a portion of population provides protection to unprotected individual.

•The higher the number of immune individuals, the lower the like hood that a susceptible people will come in contact with an infectious agent.

•Resistance to spread of infectious disease in a group because of few susceptible members, making transmission unlikely.

Vaccine

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Vaccine is a substance that is introduced into the body to prevent the disease produced by certain pathogens.It consists of dead pathogens or live but attenuated (artificially weakened) organisms. The vaccine induces immunity against the pathogen, either by production of antibodies or by activation of T lymphocytes.

Types of vaccineA. Live-attenuated (weakened) vaccines: contain modified strains of a pathogen

(bacteria or viruses) that have been weakened but are able to multiply within the body and remain antigenic enough to induce a strong immune response.

B.Killed-inactivated vaccines:To produce this type of vaccines, bacteria or viruses are killed or inactivated by a chemical treatment or heat.

C.Sub-unit vaccines•Subunit vaccines include only the antigens that best stimulate the immune system.

•In some cases, epitopes are used—the very specific parts of the antigen that antibodies or T cells recognize and bind to.

•Subunit vaccines contain only the essential antigens and not all the other molecules that make up the microbe, the chances of adverse reactions to the vaccine are lower.

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D. CombinationIf more than one kind of immunizing agent is included in the vaccine it is called a mixed or combined vaccine.

The advantage of combined vaccine is as below:

1.simplify administration 2.reduce cost 3.improving timeline of vaccination 4.reducing the storage• Example of mixed vaccines are DPT,DT,DP,MMR,etc.

• POLYVALENT: It is prepared from 2 or more strain of the same species

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vaccine Example

Live, attenuated

Measles, mumps, rubella (MMR combined vaccine)Varicella (chickenpox)Influenza (nasal spray)Rotavirus

Inactivated/Killed

Polio (IPV)Hepatitis A 12

Combined DPT,TT

Subunit/conjugate

Hepatitis BInfluenza (injection)Homophiles influenza type b (Hib)Pertussis, Diphtheria, tetanus

Why Immunization ?Key strategy to child survivalProtecting infants from diseases.

Lowers morbidity and mortality rates in children.

Indicator of a strong primary health care system.

What Is EPI?• Expanded program on Immunization (EPI) is a world health organization

program, with the goal to make vaccines available to all children throughout the world.

SCOPE OF EPIExperience with smallpox eradication program showed the world that

immunization was the most powerful and cost-effective weapon against vaccine preventable diseases.

In 1974, the WHO launched its “ Expanded program of immunization” (EPI) against six most common preventable diseases (diphtheria, pertussis, tetanus, polio, tuberculosis, measles and recently added pneumococcal vaccine).

“Expanded” Means?

Expanding the number of diseases to be covered

Expanding the number of children and target population to be covered

Expanding coverage to all corners of the country and spreading services to reach the less privileged sectors of the society.

Component Of EPI: Routine Immunization: Children 0-23 months – immunization with 8 EPI antigens Pregnant ladies by TT.

Supplemental Immunization Activities: Routine immunization does not ensure 100% coverage of the mobile population i.e. nomads, NAs, hard to reach areas / missed areas. So SIAs are scheduled to ensure coverage of this population / areas. NIDs / SNIDs: children < 5 years receive polio drops (3-days campaign)

Disease Surveillance: To detect every case of target diseases, the suspected cases of seven VPDs are reported by health facilities to the district health authorities for immediate launching of the control measures.

Mopping up: Special campaigns 5-8 km around the infected locality to localize the disease and stop its transmission.

The objectives of EPI:1. To achieve 100% coverage with all EPI vaccines.

2. Eradication of polio to maintain polio free status.

3. Elimination of measles.

4. To Reduce Seroprevalence Of HBsAg to < 1% among under five.

5.Elimination of Neonatal Tetanus .

6. To maintain zero level of diphtheria.

7-Prevention of severe forms of TB ( TB meningitis &military

TB).

8- To reduce the incidence of whooping cough

9- To Reduce the incidence of Bacteria Meningitis due to haemophelus influenza.

10- To Maintain Immunization Safety.

11-To prepare for introduction of new vaccines

Somalia EPI • EPI Vaccines • All vaccines used in Somalia by EPI program are safe, procured

through UNICEF from manufactures pre-qualified and accredited by WHO.

• The national EPI Programme provides the following vaccines: • BCG: It contains live attenuated Mycobacterium bovis (M. bovis), and comes

in powder form. It must be reconstituted with a diluent before use. It is essential that only the diluent supplied with the vaccine be used. BCG vaccine should be kept at 2°C–8°C after reconstitution. Any remaining reconstituted vaccine must be discarded after six hours or at the end of the immunization session, whichever comes first.

Somalia EPI • Oral Polio Vaccine (OPV): It is prepared from attenuated live polio virus, and is presented

as a liquid vaccine that is provided in glass vials with droppers in a separate plastic bag. In consultation with global partners, the country will make an informed decision on the introduction of IPV and phasing-out of OPV.

• Pentavalent DTP-HepB+Hib vaccine: It contains diphtheria toxoid, tetanus toxoid, pertussis, Hepatitis B and Haemophilus type b vaccine; and is provided as liquid form in vials of ten doses.

• Measles vaccine is provided as a powder, with a diluent in a separate vial. Before it can be used, it must be reconstituted. It is essential that only the diluent supplied with the vaccine be used. After reconstitution measles vaccine should be kept at 2°C–8°C. Any remaining reconstituted vaccine must be discarded after six hours or at the end of the immunization session, whichever comes first.

• Tetanus Toxoid (TT) is provided as a liquid in vials and also in prefilled auto-disable injection devices.

EPI SCHEDULE

Immunization schedule• According to the recommended schedule all children will receive one

dose of BCG vaccine, 3 doses of DTP-HepB+Hib, 4 doses of OPV, and one dose of measles vaccine before their first birthday/First year.

• Table 1: Routine immunization schedule for infants, 0 -11 monthsAge Vaccines

Birth (up to 1 week) BCG OPV0

6 weeks DTP-HepB+Hib1 OPV1



9 months MCV1

18 months MCV2

Immunization schedule for pregnant women and WBCA (15- 45 years)

Dose Time for administration Duration of protection

TT 1 at first contact OR as early as possible during pregnancy None

TT 2 at least 4 weeks after TT1 1-3 years

TT 3 at least 6 months after TT2 5 years

TT 4 at least 1 year after TT3 10 years

TT 5 at least 1 year after TT4 For all child bearing years

Summary of routes of administration and injection sites

Vaccine Route of administration Injection site

BCG Intradermal Upper Left Arm

DTP-HepB+Hib Intramuscular Outer mid-thigh (Right)

OPV Oral Mouth

Measles Subcutaneous Upper Right arm

Tetanus toxoid Intramuscular Outer, upper arm (Left)

Cold Chain•The ‘cold chain’ is the system of transporting and storing vaccines at recommended temperature from the point of manufacture to the point of use.

Manufacturer

Distributor

Vaccine Depots

Provider office

Client

Why is the cold chain important ?1.Vaccines are: Biological products lose potency with time Process irreversible

and accelerated if proper storage conditions are not adhered to.

2. Assurance in potent product and vaccine programmes

Professional responsibility

Confident the vaccines you give will be effective

Public Health responsibility

Public confidence in immunisation programmes

3. Ensuring maximum benefit from immunisationsResponsibility not to waste scarce NHS resourcesReduce wastage from errors

4.Compliance with SPC/ManufacturerAny vaccine that has not been stored at a temperature of 2-8ºC as per its licensing conditions is no longer a licensed product

Cold chain storage

equipmentWalk in cold rooms

Deep freeze

rs

Ice lined

refrigerators

A. Walk in cold rooms(WIC)At regional level

Storage up to 3 months

Serve 4-5 districts

B. Deep freezersAt district & PHC levels

Temp :- -15oc to -25oc

At PHC, used only for the preparation of ice packs

In case of power failure these freezers can maintain the cabinet temp. for 18-22 hours

20-25 icepack can be prepared by a 140L in deep freezers with continuous electric supply of 8 hours.

C. Ice Lined Refrigerators(ILR)

Both at district and PHC levels

Temp :- +2oc to +8oc

ILR’s are top opening, can hold cold air inside better than front opening refrigerators

It can keep vaccine safe with 8 hours of continuous electric supply in a 24 hours period.

• Arrangement of vaccine order top to bottom:

Hepatitis B DPT & TT BCG Measles OPV• Discard any frozen hep.b, DPT, & TT.

• Keep spaces between boxes• Measles & OPV can be kept over 2 rows of empty ice-packs on the floor of the ILR.

Vaccine Stability• Sensitivity to HEAT

OPVMeaslesBCGMMRHepatitis BDT

• Sensitivity to COLD

HepB and combination

Influenza *BCG

(*Freeze

dried)

MOST SENSITIVE

Temperature must be recorded twice in a day with dial thermometer

LEAST SENSITIVE

Light Sensitive

Sensitive to strong light, sunlight, ultraviolet, fluorescents (neon)

OPVMeaslesMMRVaricella Meningococcal C ConjugateMost DTaP containing vaccines

Vaccines should always be stored in their original packaging until point of use to protect them from light

Vaccine Storage

Use a dedicated vaccine fridge

Safeguard electricity supply

No more than 50% full

Place vaccines in clearly labelled plastic mesh baskets

Group vaccines by type (Paediatric, Adult, Adolescent)

Defrost/calibrate fridge regularly

Ensure back up facilities are available in the event of fridge failing

X No food or medical specimens

X Do not place fridge in direct sunlight or near heat source

X Do not store vaccines for more than 1 month at PHC.

X Do not store vaccines in fridge doors or in solid plastic trays/containers within the fridge

X Keep vaccines away from fridge walls and cold air vents

Picture taken from www.medisave.co.uk

DO’sDON’T’s

Transporting Equipment

Cold boxes

Vaccine carriers

Day carriers

Used for transport of vaccinesFully frozen ice packs placed at the bottom and sidesDPT, TT, DT should not be kept in direct contact

1.Cold boxes

Used to carry small quantity of vaccines(16 to 20 vials)For out of reach sessions4 icepacks are used

2.Vaccine

carriers

3.Day carriersUsed to carry very small quantities of vaccines(6 to 8 vials)For a near by session2 icepacks are usedFor only 2 hours period

ICE PACKS•It contains water & no salt should be added to it.

•The water should be filled up to the level marked on the side.

•If there is leakage such icepack should be discarded.

Vaccine Vial Monitor(VVM)VVM is a label containing heat sensitive material that is placed on a vaccine vial to register heat exposure over time

Vaccine vial monitor

Stage 1

• Inner square lighter than outer circle

Stage 2

• Inner square still lighter than outer circle

Stage 3

• Color of inner square matches the outer circle

Stage 4

• Color of inner square darker than outer circle

Combined effects of time and temperature cause the inner square to darken gradually and irreversiblyVVM does not directly measure the vaccine potency but gives info about the main factor that affects potency

Epi seminar

Health & Medicine