Kafue College of Health Sciences
Diploma in Clinical medicine
Immunology
IMMUNIZATION
P. Zulu
Outline
Introduction Contraindications and
precautions
How vaccines work
Immunizations Schedule
Types of Vaccine In Zambia
Vaccine Dosing Through Vaccine Potency, Safety
the Lifespan And AEFI
Vaccine Components: safe The Cold Chain
and Effective
summary
Introduction
Definition of Terms
• Immunization: The process of protecting a
person against a disease by introduction of a
suitable antigen in the host’s body. Make somebody
resistance to disease.
• Immunity: The resistance possessed by a body to
infectious diseases, foreign tissue, foreign non-toxic
substance and other antigens.
• Immune: Protection against infectious diseases,
foreign tissue, foreign non-toxic Substances and
antigen.
Introduction
Definition of Terms
• Natural immunity: Immunity acquired from
exposure to the disease organism through infection
with actual disease
• Vaccine-induced immunity: immunity acquired
through the introduction of a killed or weakened
form of the disease organism through vaccination
• NOTE: Either way (through natural or vaccine-
induced immunity), if an immune person comes into
contact with that disease in the future, the body
immediately produces antibodies
Introduction
Definition of Terms
• Passive immunity: immunity provided when a
person is given antibodies to the disease rather than
producing them through his or her own immune
system( Example fetus and newborn babies acquire
passive immunity from their mothers)
• NOTE: Patients can also get passive immunity
through antibody containing blood products such
as immune globulins (antibodies)
• NOTE: Unlike passive immunity, active immunity
is long–lasting and sometimes life-long
Introduction
Definition of Terms
• Vaccine: This is a suspension of micro-
organisms or toxoid or vector virus or mRNA
or subunit which are either killed or
attenuated . (This is prepared from living
organisms which through long cultivation have
lost their virulence). Used to protect against
disease.
• Vaccination: This is the inoculation with the
vaccine in order to protect against a disease.
Introduction
We need to realize the full benefits of
immunization
Immunization saves lives and keeps people
health
It saves about 3 million lives annually (yearly)
Vaccines protect against infectious diseases
For example: Cholera, rabies, measles, tuberculosis,
tetanus, poliomyelitis, Diphtheria (attacks membrane of
throat), Hepatitis B virus (liver damage and liver cancer),
Human papilloma virus (cervical cancer), pertussis
(whooping cough), Covid-19 ( affects the lungs-
pneumonia)ETC.
Covid-19
Cervical Cancer
Introduction
Vaccines can eradicate disease (get rid of the
disease completely)
Immunization eradicated smallpox (caused by
poxvirus)
Immunization has reduced poliovirus by more
than 99%
NOTE: Vaccines protect the community when
sufficient proportion of a population is immune to
an infectious disease to make its spread from
person to person unlikely
Introduction
How vaccines work
• The body is exposed to a weakened or dead
pathogen (Disease causing agent such as bacteria
or virus)
• The body's immune cells (B cells) make
antibodies to attack the weakened or dead
pathogen
• If the body is attacked again, the body will be
prepared with antibodies and memory B-cells-to
attack the real pathogen.
Introduction
How vaccines work
• Vaccines protect the community
NOTE
• When no one is immunized, a disease spreads
through the population
• When some of the population is immunized,
disease spreads through some of the population
• When most of the population is immunized,
spread of the disease is constrained (restricted)
Types of vaccines
Live attenuated: contain weakened pathogen,
require one to two doses( booster doses). Example
rotavirus, varicella
Inactivated: contain killed pathogens, require
several doses(booster shots) Example rabies, hepatitis
B
Subunit: Contain killed, antigen component of
pathogen. Require several doses (booster shots).
Example Human papilloma virus, Hepatitis B.
Types of vaccines
Toxoid: Contain toxin made by pathogen. May
require booster shots. Example tetanus, Dipththeria
and pertussis . Immune system targets the toxin and
not instead of the whole germ
Messenger RNA vaccines: These make proteins to
trigger an immune response. They don’t contain a
virus hence no risk of causing disease. Example covid-
19
Viral Vector Vaccines: Use a modified version of a
different virus vector to deliver protection. Used to
protect against Ebola and covid-19
Ebola
Vaccine Dosing Through the Lifespan
Some vaccines provide life-long immunity from a
single dose.
Others provide greater protection after multiple
doses
New vaccines are needed frequently for pathogens
that mutate often (such a influenza, covid-19)
NOTE: Vaccines are not just for children only- even
older populations need targeted protection from
certain diseases, for example covid-19 and Human
papilloma virus.
Vaccine Components: safe and Effective
Components that:
1. Provide immunity
Antigens-stimulate antibody production
Adjuvants (antigen-enhancing/ enhancing agent)
2. Keep vaccines safe and long lasting
Preservatives
Stabilizers
3. Used during production of vaccine
Cell culture material
Inactivating ingredients
Antibiotics
Contraindications and precautions
Contraindications and precautions are conditions
under which vaccines should not be administered
Majority of these conditions are temporary
so often immunization can be administered later
when the condition no longer exists
Contraindications and precautions
Contraindications
A rare condition in a recipient (patient or client)
that increases the risk for a serious adverse reaction
The only contraindication applicable to all vaccines
is a history of severe allergic reaction after a prior
dose of a vaccine or vaccine constituent
Contraindications and precautions
Precautions
A condition in a recipient (patient or client) that
may increase the risk of a serious adverse reaction,
might cause diagnostic confusion, or might
compromise the ability of the vaccine to provide
immunity
Vaccine maybe administered if the benefit from the
vaccine is judged to outweigh the risk
Immunizations Schedule In Zambia
• It is a requirement that all children should receive
all doses of the antigen before their first birthday.
• Immunization services are integrated with other
Primary Health Care (PHC) services such as
growth monitoring and promotion (GMP), health
education, micronutrient supplementation and
Family planning in the Child Health Week
immunization activities.
Immunizations Schedule In Zambia
• Immunization coverage in Zambia is higher than
in most sub-Saharan African countries with
coverage rates for measles, DPT3 and polio in the
range of 80 – 85% and BCG at above 90% of the
eligible populations.
Immunizations Schedule In Zambia
Target Groups
• Children under the age of 5. The priority is given
to those between 0-11 months.
• School children in grade1
• Pregnant Women (passive immunity-protects the
new born babies)
• Women of child bearing age between 15-45 years
• NOTE:Some times all age groups become target
groups (in the case of covid-19)
• The schedule is divided into four (4) strategies,
that is A, B, C and D
Immunizations Schedule In Zambia
STRATEGY A – Static Units(at health facility)
STRATEGY B – Mobile Units
STRATEGY C – School Health Services
STRATEGY D – TT Immunisation
STRATEGY A – Static Units
• This is done at the health facility which has a
refrigerator and provides MCH (mother to child)
services.
• Multiple vaccines such as BCG (Bacille Calmette-
Guerin), OPV (oral polio vaccine), DPT (Diphtheria
pertussis) + Hib( haemophilus influenza type B)
+Hepb (Hepatitis B) and measles can be given at the
same visit.
• All eligible children should be given immunization
at every contact with a health facility if they come for
under 5 services.
• All children with symptomatic HIV/AIDS should not be
given BCG and yellow fever but the other vaccines can be
given (WHO/UNICEF recommendations).
Recommended Immunisation Schedule or Childhood vaccination.
TABLE 1 .
Vaccine/mic Protection Age Dose Route Site Remarks
ro- against
nutrient
BCG TB At birth 0.05 mls Intra dermal Upper Should not be
outer given in
or first aspect of HIV/AIDS
contact the left Should form a
arm
blister
between 1-3
months.
If no blister
forms, dose
should be
repeated
OPV 0 Polio 0-13 days 2-3 drops Orally Mouth If not given
within 0-13
days, can be
given at 9
months as
OPV 4.
Recommended Immunisation Schedule or Childhood vaccination cont
OPV 1 At 6 Orally Mouth To be given
Polio 2-3 drops at 4 week
weeks intervals
At 10
OPV 2
weeks
At 14
OPV 3 weeks
DPT + Hib + Diphtheria 6 wks. I.M The outer To be give on
Hep B. 0.5 ml aspect of mid thigh.
Pertussis 10wks.
the Left Causes
doses 1, 2, 3 Tetanus abscess if not
14wks thigh
Haemophilus given IM.
Influenza type B Child develops
a fever and
Hepatitis B
irritability
Recommended Immunisation Schedule or Childhood vaccination cont
Measles Measles 0.5 ml 9 months Sub- Upper arm During
cutaneous deltoid campaigns
muscle it can be
Given at 6
months
Vitamin A Night 100 000 iu 6-11 Oral Mouth Should be
blindness months given every
6 months
Vaccine Potency, Safety And AEFI
• Potency simply means strength of medicine
• Potency of vaccines must be maintained for an
individual to benefit from it.
(a) Vaccine Vial Monitor (VVM).
• The vaccine vial monitor (VVM) is a heat sensitive
device which indicates if the individual vial of
vaccine to which it is attached may be used.
• The vaccine can only be used when:
• The expiry date has not been reached.
• The VVM has not changed its colour
Vaccine Potency, Safety And AEFI
• The vaccine vial can be withdrawn or
discarded when:
- The expiry date is reached regardless of the
colour of the VVM.
- The VVM changes colour regardless of the
expiry date.
• Health workers should be vigilant in
checking the VVM and expiry dates of all
vaccines before each immunisation session.
Vaccine Potency, Safety And AEFI
(b) Adverse Events Following Immunization.
• These are vaccine induced reactions which are
usually mild and temporary.
• In rare instances, reactions following immunization
can result in serious illnesses.
• AEFI should be monitored by all providers of
Immunization services. AEFI should be
investigated and efforts made to determine its
cause.
Vaccine Potency, Safety And AEFI
• Reactions can result from:
• Programmatic errors in handling,
reconstitution or administering the vaccine.
• Nature of the vaccine or individual response
to the vaccine (hypersensitivity reactions)
• Coincidence
• Unknown cause
Vaccine Potency, Safety And AEFI
FOR EXAMPLE, THE ADVERSE EFFECT CAUSED BY
SEPTRIN IS A SERIOUS ONE(NOTE THIS IS JUST AN
EXAMPLE AS SEPRIN IS NOT A VACCINE BUT AN
ANTIBIOTIC)
STRATEGY D – TT Immunization
(Tetanus toxoid vaccine)
TT1
dates Dose Route site
TT1 At first contact 0.5 ml Intramuscular Deltoid
or as muscleOn the
Early as possible left arm.
in first
Trimester
TT2 At least 4 weeks 0.5 ml Intramuscular Deltoid
after TT1 muscleOn the
left arm.
STRATEGY D – TT Immunization
TT3 At least 6 months 0.5 ml Intramuscular Deltoid muscle
after TT2 On the left arm.
Or during
subsequent
pregnancy .
TT4 At least 1 year 0.5 ml Intramuscular Deltoid muscle
after TT3 orDuring On the left arm
subsequent
pregnancy
TT5 At least 1 year 0.5 ml Intramuscular Deltoid muscle
after TT4 orDuring On the left arm
subsequent
pregnancy
The Cold Chain
• Cold chain is the process of maintaining the potency
of the vaccines starting from the manufacturers up
to the time it is administered to the child or mother.
• Cold chain is proper refrigeration of vaccines
• This includes manufacturing of the vaccine,
transportation from the factory, storage,
refrigeration and use of cold boxes and distribution
Equipment used in the Cold Chain
• Thermometer is used for monitoring temperature.
• The ice-packs are used for keeping the vaccine cool
in cold boxes or vaccine carriers thereby
maintaining their potency.
• Vaccine carriers are small boxes used for the
collection of small quantities of vaccines for a
health Centre or for an outreach session
Storage Temperatures For Vaccines
• TT and DPT between 2 and 8 ◦C
• Measles, OPV, BCG between should be stored
frozen up to -15
• DPT and diluent should be stored at 2 – 8
degrees and never frozen. Storage is limited
to a month
summary
Immunization saves lives and keeps people health
It saves about 3 million lives annually (yearly)
Vaccines protect against infectious diseases
For example: Cholera, rabies, measles, tuberculosis,
tetanus, poliomyelitis, Diphtheria (attacks membrane of
throat), Hepatitis B (liver damage), Human papilloma virus,
pertussis, Covid-19 ETC.
Vaccines are of different types and are
formulated in different ways
summary
In some instances, vaccines are Contraindicated
and there is need of taking precautions in certain
circumstances
AEFI should be monitored by all providers of
Immunization services. AEFI should be
investigated and efforts made to determine its
cause
The cold chain is very importantant when handling
vaccines
THE END
THANK
YOU
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