Faculty of Medicine

Applied Vaccination

By

Hatim Jaber MD MPH JBCM PhD

12 -12- 2017

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Presentation outline

Time

Introduction to Immunology 14:00– 14:10

Vaccine-preventable diseases Classification of Vaccines

14:10– 14:20

Principles of Vaccination Routes of administration

14:20– 14:30

General Recommendations = Precautions and Contraindications

14:30– 14:50

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World Immunization Week • Immunization averts 2 to 3

million deaths annually; however, an additional 1.5 million deaths could be avoided if global vaccination coverage improves.

• Today, an estimated 18.7 million infants – nearly 1 in 5 children – worldwide are still missing routine immunizations for preventable diseases, such as diphtheria, pertussis and tetanus.

24-30 April

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World Immunization Week, 24-30 April 2017

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Global Vaccine Action Plan Goals of the Decade of Vaccines (2011–2020)

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Defense Mechanisms

1. External defense 2. Internal Defense 3. Immune Defense

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What is immunity?

• Immunity is the body's ability to fight off harmful micro-organisms –PATHOGENS- that invade it.

• The immune system produces antibodies or cells that can deactivate pathogens.

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Vaccination

• Vaccination is a method of giving antigen to stimulate the immune response through active immunization.

• A vaccine is an immuno-biological substance designed to produce specific protection against a given disease.

• A vaccine is “antigenic” but not “pathogenic”.

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What’s the difference between Vaccination and Immunization

• Immunization is the process of protecting people against harmful infections before they come into contact with them. It does

this by using the body’s own natural defense system, the immune response.

•

• Vaccination just means having the injection. When you are vaccinated, your body produces an immune response, just as you would if you were exposed to the infection, but without having the symptoms, and this builds up your resistance to that infection.

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Vaccine-preventable diseases

Vaccine-preventable diseases include:

• Cervical cancer

• Cholera • Diphtheria • Hep B • Influenza • Japanese

encephalitis • Measles • Mumps • Pertussis

Vaccine-preventable diseases include:

• Pneumonia • Polio • Rabies • Rotavirus • Rubella • Tetanus • Typhoid • Varicella • Yellow Fever

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Hib=(Haemophilus influenzae type b)

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Vaccine Preventable

Diseases (VPDs)

• World immunization coverage up from 10% in 1970s to 80% in 1990s, then to 77% in 2004

• Smallpox eradication achieved 1982

• Polio eradication 2005-2010 ????????????????

• Measles still kills >0.4 million per year, need for a two dose policy (MMR)

• Many new vaccines available and coming

• Costs effectiveness and priorities

• Coverage is good; Adapt and expand

•NON-Vaccine Preventable

Diseases????????

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Eradication or Control of VPDs

• Diseases under discussion for eradication –

- measles, TB, and some tropical diseases e.g. malaria and dracunculiasis

• Eradication - no further cases of a disease occur anywhere in nature; continued control measures may be unnecessary e.g. smallpox, polio

• Reducing epidemic and endemic VPDs in selected areas or target groups, may achieve local elimination

• Local elimination is where domestic circulation of a virus is interrupted with cases occurring from importation only

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Herd Immunity

• Herd immunity can be defined as the resistance of a population to the introduction and spread of an infectious agent, based on the immunity of a high proportion of individual members of the population, thereby lessening the likelihood of a person with a disease coming into contact with b susceptible.

• Example - If 90 % of the children are vaccinated for measles, the remaining 10 % of the children who are not vaccinated might not become infected with measles because most of the children (90 %) are vaccinated.

• That means transmission from infected person to other susceptible children will not be easier.

• Can lead to disappearance of diseases (smallpox) – Vaccination no longer necessary

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Types of Acquired Immunity

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Immunoglobulin and antiserum

Human normal

immunoglobulin

Human specific

immunoglobulin

Non human Ig

(antisera,

antitoxins)

Hepatitis A

Measles

Rabies

Tetanus

Mumps

Hepatitis B

Varicella

Diphtheria

Diphtheria

Tetanus

Gas gangrene

Botulism

Rabies

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Types of vaccines

1. Live vaccines

2. Attenuated live vaccines

3. Inactivated (killed vaccines)

4. Toxoids

5. Polysaccharide and polypeptide (cellular fraction) vaccines

6. Surface antigen (recombinant) vaccines.

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Types of vaccines Live

vaccines

Live

Attenuated

vaccines

Killed

Inactivate

d vaccines

Toxoids Cellular fraction

vaccines

Recombin

ant

vaccines

•Small pox

variola

vaccine

•BCG

•Typhoid oral

•Plague

•Oral polio

•Yellow fever

•Measles

•Mumps

•Rubella

•Intranasal

Influenza

•Typhus

•Typhoid

•Cholera

•Pertussis

•Plague

•Rabies

•Salk polio

•Intra-

muscular

influenza

•Japanise

encephalit

is

•Diphther

ia

•Tetanus

•Meningococcal

polysaccharide

vaccine

•Pneumococcal

polysaccharide

vaccine

•Hepatitis B

polypeptide

vaccine

•Hepatitis

B vaccine

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Routes of administration

• Deep subcutaneous or intramuscular route (most vaccines)

• Oral route (sabine vaccine, oral BCG vaccine)

• Intradermal route (BCG vaccine)

• Scarification (small pox vaccine)

• Intranasal route (live attenuated influenza vaccine)

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Vaccine administration

Intranasal route (live attenuated influenza vaccine)

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Injection site

Intramuscular Injections Site

Preterms & neonates Anterolateral thigh (junction of middle & lower third) Infants

Toddlers & older children Deltoid or Anterolateral thigh

Adolescents & adults Deltoid

Subcutaneous Injections Site

Infants thigh

>12 months Outer triceps

Intradermal Injections Site

All age Left deltoid 27

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Vaccination schedule preschool -Jordan

Vaccine Age

BCG 1st contact

DaPT1+HepB1+Hib1+IPV1 2 months

DaPT2+HepB2+Hib2+IPV2+

OPV

3 months

DaPT3+HepB3+Hib3+OPV 4 months

Measles + OPV 9 months

MMR1 12 months

DPTbooster1 +OPV booster1

+MMR2

18 months

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IAP recommendations for immunization in adolescents

Vaccines Schedule

MMR 2 doses at 4-8 weeks interval

Hepatitis B 3 doses at 0,1 & 6 months

Hepatitis A 2 doses at 0 & 6 months

Typhoid 1 dose every 3 years

Varicella 2 doses at 4-8 weeks interval

Influenza 1 dose every year

JE vaccine Catch-up up to 15 years

Tdap 1 dose followed by Td booster every 10 years

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Vaccination for travelers the most frequent vaccine-preventable diseases

and the dose schedules

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Scheme of immunization

• Primary vaccination

– One dose vaccines (BCG, variola, measles, mumps, rubella, yellow fever)

– Multiple dose vaccines (polio, DPT, hepatitis B)

• Booster vaccination

To maintain immunity level after it declines after some time has elapsed (DT, MMR).

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Changes in immunoglobulin levels with age

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Why multiple doses necessary?

• Single does may not provide sufficient immunity (e.g. HIB)

• Immunity wanes over time; “booster” dose is needed (DTaP)

• Single dose does not produce immunity for everyone (e.g. measles)

• Vaccine components change over time (e.g. influenza)

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Periods of maintained immunity due to vaccines

• Short period (months): cholera vaccine

• Two years: TAB vaccine

• Three to five years: DPT vaccine

• Five or more years: BCG vaccine

• Ten years: yellow fever vaccine

• Solid immunity: measles, mumps, and

rubella vaccines.

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Levels of effectiveness

• Absolutely protective(100%): yellow fever vaccine

• Almost absolutely protective (99%): Variola, measles, mumps, rubella vaccines, and diphtheria and tetanus toxoids.

• Highly protective (80-95%): polio, BCG, Hepatitis B, and pertussis vaccines.

• Moderately protective (40-60%) cholera vaccine, and influenza killed vaccine.

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The Cold Chain

• The "cold chain" is a system of storage and transport of vaccines at low temperature from the manufacturer to the actual vaccination site.

• The cold chain system is necessary because vaccine failure may occur due to failure to store and transport under strict temperature controls.

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Principles of vaccination

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Principles of Vaccination

1. The primary goal in vaccination is to provide protective immunity by inducing a memory response to an infectious microorganism using a non-toxic antigen preparation. It is important to produce immunity of the appropriate kind: antibody / or cellular immunity.

2. Antibodies produced as a result of immunization are effective primarily against extracellular organisms and their products e.g., toxins. Passively administered antibodies have the same effect as induced antibodies.

3. Cell-mediated immunity (T cells, macrophages) induced by vaccination is important particularly in preventing intracellular bacterial and viral infections and fungal infections.

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Principles of Vaccination

• 4.The ultimate goal of any immunization program is the eradication of the disease.

• 5.This requires that the infection is limited only to humans, with no animal or environmental reservoir, and the absence of any subclinical or carrier state in humans.

• 6.Achieving elimination requires a high level of herd immunity to prevent person to person spread.

• 7.This requires considerable infrastructure support to ensure that all at-risk populations are targeted for immunization.

• 8.This has been achieved for small pox, although we are close to the elimination of polio.

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HAZARDS OF IMMUNIZATION

• No immune response is entirely free from the risk of adverse reactions or remote squeal. The adverse reactions that may occur may be grouped under the following heads:

1. Reactions inherent to inoculation

2. Reactions due to faulty techniques

3. Reactions due to hypersensitivity

4. Neurological involvement

5. Provocative reactions

6. Others 42

Adverse events after vaccination are grouped into five categories, depending on whether they are due to:

1) • the vaccine product: an adverse event caused or precipitated by a vaccine due to one or more of its inherent properties. Example: extensive limb swelling after administration of DTP vaccine

2) • quality: an adverse event caused or precipitated by a vaccine with one or more defects, including the administration device provided by the manufacturer. Example: paralytic poliomyelitis due to failure by a manufacturer to completely inactivate a lot of poliovirus vaccine

3) • vaccination error: an adverse event due to inappropriate handling, prescription or administration of a vaccine. Example: transmission of infection from a contaminated multidose vial

4) • anxiety: an adverse events arising from anxiety about the procedure. Example: vasovagal syncope in an adolescent during or after vaccination

5) • a coincidental event: an adverse event caused by an event other than the vaccine, vaccination error or anxiety. Example: a fever occurring at the time of vaccination (temporal association) that is in fact due to a viral infection

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Main minor and severe reactions associated with vaccination

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Different type of adverse events following immunization

Vaccine reaction Event caused/precipitated by the inherent properties of the vaccine (active component, adjuvant, preservative, stabilizer) when given correctly

Program errors Event caused by an error in vaccine preparation, handling or administration

Coincidental Event that happens after immunization but is not caused by the vaccine

Injection reaction

Event arising from anxiety about, or pain from, the injection itself rather than the vaccine

Unknown The cause of the event cannot be determined

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Common minor vaccine reactions

Vaccine Local reaction (pain, redness, swelling)

Fever Irritability, malaise & non specific reactions

BCG common

Hib 5-15% 2-10%

Hep-B Adults-15% Children-5%

1-6%

Measles/MMR

10% 5-15% 50% (rash)

OPV <1% <1%

TT/DT/Td

10% 10% 25%

DPwT 50% 50% 60%

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Rare serious vaccine reactions

Vaccine Reaction

BCG Suppurative adenitis, BCG osteitis, Disseminated BCGitis

Hep-B Anaphylaxis

Measles/MMR Febrile seizures, thrombocytopenia, anaphylaxis

OPV VAPP

TT Brachial neuritis, anaphylaxis, sterile abscess

DTP Persistent inconsolable screaming, seizures, HHE, anaphylaxis, shock

JE Serious allergic reactions, neurological events

YF Allergic reactions/anaphylaxis

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Differential diagnosis of fainting and anaphylaxis

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Reactions due to anxiety about vaccination

• Fainting is relatively common, mainly among older children and adults. This vasovagal reaction may lead to loss of postural tone and consciousness

• • Hyperventilation due to anxiety about vaccination can cause light-headedness, dizziness and tingling around the mouth and in the hands.

• • Vomiting: Vomiting is a common anxiety symptom in young children. Breath-holding spells may occur, which can result in brief unconsciousness, during which breathing resumes.

• • Convulsions: An anxiety reaction to injection can, on rare cases, include convulsions. Convulsions usually occur in the context of a vasovagal reaction and syncope, soon after or with the loss of postural tone and consciousness that characterizes syncope. Such seizures are due to anoxia, are usually self-limited and benign and do not require antiepileptic drug therapy.

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Vaccination Coverage • Vaccination coverage is the percent of at risk or

susceptible individuals, or population who have been fully immunized against particular diseases by vaccines or toxoids.

• To be significantly effective in prevention of disease on mass or community level at least a satisfactory proportion (75% or more) of the at risk population must be immunized.

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No. persons immunized in specified age group

= ------------------------------------------------------------ X 100

No. persons in the age group during that year

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WHO UNICEF estimates time series for Jordan

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Vaccines Contraindications and Precautions

Who should NOT receive a vaccine? Contraindications to any routine active immunization procedure

• Severe allergy to any vaccine component • Severe reaction to same vaccine in past • Individuals with certain immunodeficiencies (live vaccines) • An acute febrile illness, malaise, cough, diarrhea, or other

symptoms requiring medical treatment.

• Children who have had convulsions, fits, cerebral damage or

irritation in the neonatal period or any neurological disorder which

appears to be active should not normally have DTP vaccine as a

routine. They should be referred for specialist advice.

• Active untreated tuberculosis.

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Contraindications to the use of live attenuated vaccines

1. Immunocomproised infants and children.

2. Patients suffering from any malignant condition such as leukemia or Hodgkin’s disease.

3. Patients undergoing treatment with corticosteroid (other than topical steroids), alkalating agents, antimetabolites or those receiving radiotherapy.

4. Organ transplantations.

5. Pregnancy,

6. Sever protein energy malnutrition or kwashiorkor???????

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There are very few contraindications to rotavirus vaccines.

1. a history of a severe allergic reaction (e.g. anaphylaxis) after a previous dose of either rotavirus vaccine or any component of the vaccine being given;

2. • severe combined immunodeficiency; the risk–benefit ratio for children with known or suspected altered immunocompetence should be assessed individually. Children and adults with congenital immunodeficiency, haematopoietic transplantation or solid organ transplantation sometimes experience severe or prolonged rotavirus gastroenteritis.

3. • a history of intussusception, which places children at greater risk than children who have never had it.

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· Minor illnesses such as upper respiratory infections or diarrhoea, mild fever (< 38.5°C)

· Allergy, asthma · Prematurity, underweight newborn child · Malnutrition??????????????????????? Under nutrition,

failure to thrive . · Child being breastfed · Family history of convulsions · Treatment with antibiotics · Dermatoses, eczema or localized skin infection · Chronic diseases of the heart, lung, kidney and liver · Stable neurological conditions, such as cerebral palsy

and Down's syndrome · History of jaundice after birth

These are not contraindications to Routine

Immunization

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Conditions which are NOT Contraindications

(cont.)

- An antibiotic course just completed.

-Congenital heart disease, chronic diseases of the chest, eg.

Cystic fibrosis (these are important indications for

immunization)

- Prematurely, or preterm delivery.

- Nappy rash.

- Breast feeding.

- Topical steroids. 58

Invalid Contraindications Minor Illness

• Low grade fever

• Upper respiratory infection

• Otitis media

• Mild diarrhea

• Only one small study has suggested decreased efficacy of measles vaccine in children with URI

• Findings not replicated by multiple prior and subsequent studies

• No evidence of increased adverse reactions

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Summary

• Current recommended vaccinations are safe and effective

• No vaccines are 100% effective or 100% risk-free

• Current recommendations based on best available scientific data

• Schedule reviewed/updated annually

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Summary and Conclusion

• Vaccination is cornerstone of PH

• Children and other groups

• Rapidly developing field

• First priority in public health after safe water and food

• National programs must be revised annually

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