14 immunization(1)

EPI(Expanded Program of Immunization)

04/11/23 EPI hand out for Midwifes BY. HK. 1

By: Habtamu K.

Learning Objectives:

• Define immunization and vaccination• List types of immunization and vaccination• Discuses determinants of immune response• Discussion of individual vaccines

– Preparations– Precautions and contraindications– Administration– Side effects– Contraindications


Introduction • Infectious diseases lead to high mortality and

morbidity in pediatric patients. • These infectious diseases range from self limiting to

long term disability such as; blindness, deafness and others.

• Magnitude of communicable disease could be reduced by maintaining:

o Good nutrition and safe watero Environmental and self hygieneo Better living environment


Cont…


Cont….

Presently Hepatitis B, H.Influenza B and pneumonia

are included under EPI target diseases nationally.

The EPI of a give country is determined by:

• Epidemiology of the diseases

• Sustainable financial support

• Well organized infrastructure


Immunization:


Active immunization• Active immunization entails the introduction of a

foreign molecule into the body, which causes the body itself to generate immunity against the target.

• This immunity comes from the T cells and the B cells with their antibodies


Passive immunization This method of immunization begins to work very

quickly, but it is short lasting, because the antibodies are naturally broken down, and if there are no B cells to produce more antibodies, they will disappear.

The antibodies can be produced in animals ("serum therapy") although there is a high chance of anaphylactic shock because of immunity against animal serum itself.

Thus, humanized antibodies produced in vitro by cell culture are used instead if available.


importance of immunization

• Eradication of disease Eg: smallpox

• Elimination of disease Eg: polio

• Control of disease Eg: diphtheria


Immunizing agent:

Vaccine :a protein, polysaccharide or nucleic acid

delivered to body to produce immunity

Toxoid :a modified bacterial toxin (not toxic but

capable of producing antitoxin)

Antitoxin: antibodies derived from human or animal

serum after stimulation with specific antigen


Determinants of immune response

1. Age –presence of high concentration of maternal antibody. -immature response in the 1st 4 months .

e.g. measles vaccine 2. Route of administration- - Mucosal secretion of antibody ( ImA.) e.g. OPV - Using an improper route to administer the vaccine

may reduce the immune response. E.g. Subcutaneous hepatitis B at buttock less

immunogenic than IM at deltoid


Dete….3. Nature of vaccine- - live attenuated vaccine s induce immunity with

single dose which lasts longer than inactivated ones.

4. Genetic –individuals genetically vary in their ability to respond to the same vaccines.

5. Potency of the vaccine- ensuring potency of the vaccine , especially live attenuated, requires keeping the cold chain.


Strategies of immunization

I. Static : at health facilitiesII. Out-reach: in the community levelIII. Intensive : campaign/ immunization dayIV. Mop up: revision of campaign for those who are

not vaccinated


Constituents of vaccine

Vaccination - administration of any vaccine or toxoid for prevention of disease that constitutes:

»Protein , polysaccharide ,nucleic acid»Preservative/stabilizer/antibiotics»Adjuvant (salts)»Suspending fluid »Component of organism: like influenza

vaccine


Types of vaccines:Live attenuated:- Prepared from attenuated strains that render them

non-pathogenic .- Usually effective with one dose as they replicate in the

host and provide antigenic stimulation for long time.- The drawbacks of live attenuated vaccine are:

Reversion to wild type can lead to diseaseThey can cause severe disease in

immunocompromised childrenSome people exhibit hypersensitivity to viral

antigen. e.g. BCG, MMR, OPV, Varicella, Measles.


Type cont…

• Inactivated or killed :i. Inactivated whole organism :

e.g. Hepatitis A, whole cell pertussis ii. Detoxified exotoxins :

e.g. Tetanus , Diphtheria iii. Purified protein antigen:

e.g. Acelluar pertusses , Hepatitis Biv. Polysaccharide: e.g. Capsular Meningococcal


Types Cont…

v. Conjoined Vaccines- polysaccharides are being conjugated with protein b/c they have;

. Short-term antibody production . Poor immunegenicity in infants and . No memory for future antigens- So they are conjoined with other proteins to improve

their immunological response - E.g; Hib, meningococcal, pneumococcal


Immune response to vaccine:

• In live attenuated vaccines ,the organisms multiply in recipient so it is more like the natural infection ,so it is likely to produce life long protection after 1st dose of vaccine.

• Killed vaccines :less antigenic so usually need booster doses.


Types of vaccine BCG (Bacille Calmette Guerin)vaccine

• There is evidence that BCG provides appreciable protection against tuberculosis meningitis (50-80%) and miliary disease.

• live-attenuated strain of M.bovis• It is frozen dried vaccine in powder form (needs

diluents 1 ml)• Dose/route - Id 0.05ml for neonates - 0.1ml for older child• Given intra dermal at Rt deltoid muscle


BCG cont…

• Vaccine efficacy - 0-80% for pulmonary - 75-90% for severe TBC• Use diluted vaccine only for one session• Keep between 2oc- 8oc even as low as -20 oc• Stand in/on ice pack• Keep away from sun light and cover with black paper


BCG cont…

Side effects:1. Koch phenomenon/small red tender swelling/2. Indolent ulcer- local lesion, papule, 2 weeks after

vaccination. At 6 weeks (crust, detaches, ulcerates) ,then a 5mm scar (typically round and slightly depressed) remains

3. Deep abscess- secondary to deep injection - Small abscess might develop, 4-6 wks.


BCG cont….4. Lymphadenitis- Involvement of lymph node / - Serious Lymphadenitis :Persistent, recurrent or

multiple5. BCG osteitis- disseminated BCGosis in immune

compromised children ( 1: 1,000,000)Contraindications: Only “Symptomatic HIV infection (i.e. AIDS)” is

a contraindication for BCG according to WHO Sever immunodeficiency

Precaution-moderate or severe illness with/without fever


Polio Vaccine• Vaccines-live-attenuated virus (OPV, Sabin) -killed, injectable (IPV, Salk)• OPV -Given orally 2 drop Advantages of OPV over IPV - Easy to administer - superior antibody response - Provides rapid immunity within 1wk - Provides Herd Immunity• Easily damaged by heat, store /keep at 0-8 oc at

health facilities & -15 to -25oc at central, regional and zonal level


Polio…• Can be frozed and refrozen without damage• Start at birth to 14 days OPV 0, then at 6, 10, 14wks• Wait at least for 4wks between the doses• Repeat it if the child spit it out• Do not count the dose if the child has diarrhea during

vaccination & repeat week later.Contraindication - sever immuno-suppression Precaution- chock of children


Penta valent (DPT,HiB &HBvAg)• Diphtheria and tetanus- are toxoids• Pertussis- killed bacteria• H/Influenza- conjugate vaccine• Hepatitis BV- surface antigen

• Start at six weeks of age then at 10wk and 14wks• 0.5ml I/m at outer middle of thigh• Is liquid vaccine, shake it well before use• Easily damaged by heat & freezing


Tetanus Prepared by inactivating the toxin by formaldehyde Even if there was previous disease, the child should

be vaccinated since disease doesn’t confer immunity Neonatal tetanus is prevented by maternal

immunization(3doses before & 2doses during pregnancy at 6wks interval, 2nd dose at least 4-6wks before delivery)

Efficacy= 85-95%


Diphtheria • Prepared from toxin by formaldehyde• Almost always given with tetanus & pertussis as DPT• Efficacy= 80-90%

Pertussis Vaccine• Whole cell vaccines prevent serious illness• Do not protect completely against infection• Efficacy & antibody levels wane with time• Efficacy= 80%


Hepatitis B Virus vaccine • Consists of purified inactive sub-unit of the virus, not

infectious, is a very safe vaccine • Not contraindicated in immunodeficiency• HBV is very effective in perinatally acqired

infection(85%) and 80-95% effective in postnatally acquired infection

• Routine vaccination is given to all infants, children and adolescents

• Infants of HBsAg-positive= Ig and vaccine within 12hrs of birth at separate site,2nd dose at 1-2mo and 3rd dose at 6th month of age

• Infants born to HBsAg-positive mothers should receive the vaccine and HBIG within 12hr of birth.


Haemopholus Influenza-type B

• Hib- common cause of; . meningitis . pneumonia . epiglottitis . sepsis . arthritis • Conjugated vaccine• Safe (almost free of side effects) and effective• Can be given combined with other vaccines(DPT)• If a child presents after 1yr of age; - age 12-15months= 1st dose(today), 2nd after 2mo

and 3rd after 6mo - 15-59mo= 1st and 2nd dose only


Side effect of pentav.

• Majority are of pertussis Encephalopthy Convulsion Collapse /shok(hypotonic-hyporesponsive) Abscess (treat with antibiotics, warm compress)

• Mild Problems (Common): - Fever, Redness, swelling, Soreness (1 in 4)

Fussiness ,Tiredness or poor appetite and Vomiting (1 in 50)

- These problems occur more often after the 4th and 5th doses of the DTP series than after earlier doses.


Side eff. Cont…

• Moderate Problems (Uncommon): Seizure (1 in 14,000), Non-stop crying for 3 hours

or more (1 in 1,000), High fever (1in 16,000) • Severe Problems (Very Rare) : - Serious allergic reaction (1 in a million dose) - Long-term seizures, coma, or lowered

consciousness , Permanent brain damage. so RARE that it is hard to tell if they are caused

by the vaccine.


Precautions - fever >40.5 within 48hrs - collapse or shock-like effect within 48hrs -seizure in 3days - persistent, inconsolable cry >3hrs within - 48hrs during the previous dose - moderate or severe illness with/without feverContraindications: 1. Encephalopathy (coma ,altered level of

consciousness ,prolonged seizures ) within 7 days of previous dose of DPT.

2. Progressive neurological disorder till neurological state is clarified. 3. Severe allergic reaction after a previous dose


Measles vaccine• Live-attenuated, frozen dried vaccine• Efficacy=85%• Needs dilutes of 5ml for reconstitution• 0.5ml subcutaneously at outer upper arm• Given at 9 month after birth• May be given in case of malnutrition, refuges,

hospital admission & affected by disaster• Easily damaged by heat• Store b/n 2-8 oc at health facilities &• -15- -25oc at central, regional and zonal level

04/11/23EPI hand out for Midwifes BY.

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Measles cont…

Side effect:

Fever & rushes 1-3 days

Encephalopathy Convulsion( rare)

Contraindication:

Anaphylactic shock Moderate-sever illness Prematurity Sever malnutrition Penicillin allergy Immunodeficiency


Tetanus toxoid

A weak toxin ( toxoid) A liquid injectable vaccine Store & transport at 2-8oc Never frozen TT Target groups are 15-45 yrs of aged women 0.5ml IM at upper arm 5 doses are recommended Pain, redness & swelling for few days


TT cont…

Dose Schedule Duration of protection in years

TT1 Starting dose Initiation of immunity

TT2 4wks after TT1 3 years protection

TT3 6 months after TT2 5 years protection

TT4 1 year after TT3 10 year protection

TT5 1year after TT4 Life long protection


Vitamin A• Administer with measles vaccine• Children--< 6 month are recommended -- 6- 12 months=100000IU --12-59months 200000IU • Not given for child with edema• Indicated for:

– Measles case (90%)- Immunodeficiency - Evidence of vit. A deficiency- Impaired intestinal absorption - Moderate to sever malnutrition- Immigration


Vaccine schedules:

• Generally a vaccine is recommended at the youngest age at which significant risk of a disease and complication exist and at which protective immune response is expected.

• Either universal schedules or for selected populations e.g. :

Specific diseases (nephrotic syndrome…) Travel (yellow fever vaccine…) Post exposure (rabies…)


Contact Age of child Vaccines

1 At birth BCG and OPV zero

2 6weeks DPT1-HepB1- HIB1 and OPV1

3 10weeks DPT2-HepB2-HIB2 and OPV2

4 14weeks DPT3-HEPB3-Hib3 and OPV3

5 9th month Measles and Vitamin A


Schedule cont…

• No need of restart interrupted vaccination• There is no maximal interval b/n doses of penta,

polio & TT• The minimal interval is 4wks• Acceptable proof for immunization are presence of

scar for BCG & immunization card


How we keep potency of vaccine?• Vaccines are sensitive to heat and freezing and must

be kept at the correct temperature• Vaccines potency cannot be regained once it is lost• The system used for keeping and distributing

vaccines in good conditions called cold chain.• Cold chain- method of keeping vaccines cold to

insure its potency• Cold chain consists of a series of storage and

transport links, all designed to keep vaccines with in an acceptable range of temperature until it reach the user.


Potency cont…• Maintenance of cold chain requires vaccines and

diluents to be: – Collected from the manufacturer or an airport as

soon as they are available.– Transported between 2oc and 8oc from the air port

and from one store to another.– Transported between2oc and 8oc range during

immunization sessions and– Kept between 2oc and 8oc range during

immunization sessions and return to health facility from out reach.

– Check temperature 2 times daily


Cold chain equipment used in heath facilities

1. Refrigerators: – used for storing vaccines at the right temperature– May be powered by electricity , gas or kerosene– Electric refrigerators are least costly and easiest to

maintain

2. Cold boxes:– Helps to store vaccines for several days (from 2 to 7

days)– Are insulated containers that, when lined with frozen

ice packs, are used for collecting large quantities of vaccines, and transporting large quantities of vaccine.


Equipments. Cont…3. Vaccine carriers:

– Are insulated containers that when lined with frozen ice packs are used for collecting small quantities of vaccines (diluents for health facility , and transporting small quantities of vaccine by vehicle or motorcycles or mule back)

4. Foam pads: – It is a piece of soft foam that fits on top of ice

packs in vaccine carriers.– Are some incisions on it to allow vaccines to be

inserted in the foam

04/11/23EPI hand out for Midwifes

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Equip. cont…

5. Ice packs: – Are flat, square plastic bottles that are filled with

water and frozen ice packs are used to keep vaccines cool inside the vaccine carriers.

– Helps to store vaccines for only one day.


Cold chain monitoring equipments 1) Vaccine vial monitors (VVM)

– Is a label that changes color when the vaccine vial has been exposed to heat over a period of time.

– As the vaccine exposed to heat a color which looks like a square inside a circle becomes darken

– Note: Use only vials with inner square that are lighter in color than the outside circle.

– Vials with VVM in which the inner surface has begun to darken but is still lighter than the outer circle should be used before the vials with a lighter inner square.


Cold chain mon. cont… 2) Vaccines cold chain monitoring card

(VCCMC)– Is a card (different color back ground cards exist

for different language versions) with an indicator strip that changes color when vaccines are exposed to temperature that is too high.

– It is used to estimate the length of time that vaccine has been exposed to high temperatures.

3) Thermometers:(dial or stem) – On the dial thermometer, the needle moves

around the scale, pointing to plus (+) numbers when it is warmer and to minus (-) numbers when it is colder.


Cold chain mon. cont…

– On stem thermometer, colored fluid in the bulb moves up the scale as it become warmer and down as it becomes colder.

4) Freeze indicators(freeze watch and freeze –tag)– Are sued to warn of freezing and are packed with

vaccines that are sensitive to freezing temperature (<0oc): DPT, T, DT or HepB and Hib vaccines.


Cold chain mon. cont…


Immunization monitoring chart• Shows the progress in raising immunization• Done by comparing the number of people you

actually immunize each month with your coverage targets.

• The direction of the monitor line is interpreted as:o Very successful=monitor line is 75 - 100% target line.o Moderately successful= monitor line (50% -75%)o Not very successful= ( 25% -50% )o Not successful= monitor line <25% of target line


Causes of low immunization coverage

1. Dropout: a child or a woman who failed to return for subsequent doses for which he/she is eligible.

• Possible causes :– Unsure of date of return– Failure to explain the need of completing vaccination

and possible side effects – Negative attitudes to HW– Mothers usually busy– Long wait at vaccination center– Vaccination centers are opened at inconvenient dates

or hours


Causes of low imm. cont…


Causes of low imm. cont… 2. Missed opportunity• Current policy states that all children and mothers at

health facility for any reasons should be screened for immunization status and vaccinated if eligible

Causes:– Health workers do not know the policy– False C/I to immunization. E.g, not giving polio vaccine

to child with diarrhea.– Logistic problem– HW vaccinate women with TT only if they are Px– Acceptability: culture, rumors, belief etc


Causes of low imm. cont… 3. Culture and belief:

4. Lack of geographic access

5. Problems associated with vaccines

6. Fail to know the target population

7. Low/ lack of community involvement and inter spectral collaboration

8. Ineffective management:

9. Problem related to supplies, cold chain and maintenance

04/11/23EPI hand out for

Midwifes BY. HK.54

Tasks at immunization session

• Mobilization of population• Keeping orders of the clients• Weighting• Screening and treating• Registration • Health education/information• immunization


Loading of Vaccines in a refrigerator

• Freezing compartment = ice packs• Top shelf= OPV and measles vaccines• Middle compartment=BCG vaccines• Lower compartment= Penta & TT• Don’t put dilutes out side


Special conditions:

• Most vaccines can be given simultaneously without impairment of vaccines effectiveness or safety

• Breast feeding is not a contraindication to any vaccine ,although most live attenuated vaccines replicate in mother they are not excreted in human milk.

• Lapsed immunizations:If interval between vaccine doses exceed those

recommended ,this does not adversely affect the immune response provided the series is completed, so no need to restart the series or to give extra doses.


Preterm infants:

• Immune response to vaccination is a function of postnatal age rather than gestational age

• Prematurity does not increase the incidence of vaccine related adverse effects

• Doses are same as those for term infants (NOT reduced)

• Should be vaccinated at same chronological age as full term ,according to schedule .


14 immunization(1)

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