Immunity and vaccines for exam 3

SO....
HOW DO YOU FIGHT
BACK?

Monday, February 27, 2012

HOST FACTORS: WHAT YOU
DO TO FIGHT INFECTIONS
Immune System
Overview

Factors that affects the
immune status of the
host

age, nutrition, hygiene,
etc

BEFORE THE IMMUNITY...


OVERVIEW: HOW WE FIGHT
INFECTIONS...

www.youtube.com/watch?v=T_4TrNRa3v8

THE CELLS...


INNATE HUMORAL :
THE COMPLEMENT


THE
COMPLEMENT
SYSTEM &
THEIR
FUNCTION


INNATE
CELLULAR
MONOCYTES

dendritic cells (antigen presenting cells)

macrophages (ingest foreign cells)

NATURAL KILLER CELLS

releases proteins to kill foreign cells

GRANULOCYTES

mast cells (releases histamines during allergic reactions)

neutrophils, eosinophil, basophils


DENDRITIC CELLS &
ANTIGEN PRESENTATION


MACROPHAGES


NATURAL KILLER CELLS


MAST CELLS


THE PHILS...
NEUTROPHILS

EOSINOPHILS

BASOPHILS
INFLAMMATION


ADAPTIVE
HUMORAL


ADAPTIVE
CELLULAR
B cells Th

plasma cells = helpers

differentiates to activates humoral
antibodies response (immune cells)

memory cells = for Tc
secondary exposure to cytotoxic
antigens
kills and clears


B CELLS


T HELPER CELL


CYTOTOXIC T CELL


MHC
CLASSES
A. Which T cell will
perform

B. Which pathogen type

Intracellular Extracellular

INFECTION BY BACTERIA
Bacterial Infections Are Neutralization Of Toxins
Eliminated By Humoral
Exotoxins (Ex.
Immunity
Diptheria)
Exception: intracellular
Endotoxins (Ex. LPS)
bacteria Ex. TB
Lysis Of Bacteria Thru
Antibodies Eliminate
Complement Pathway
Bacteria Or Bacterial Toxins
Bacteria Enter Host Thru
Opsonization Of
Bacteria Respiratory Tract, GI Tract,
Genitourinary Tract, Skin

EVASION BY BACTERIA
Some Bacteria Have Pili

Some Bacteria Secrete Adhesion Molecules (Bordetella pertussis)

Immune System Response To Attachment Is IgA

Prevents Attachment

Some Bacterial Evade IgA Thru Proteases That Decrease ½ Life Of
IgA

Ex. Haemophilus inﬂuenzae

Some Bacteria Avoid Phagocytosis By Surrounding Themselves In
A Polysaccharide Capsule. Ex. Streptococcus pneumoniae


OVERZEALOUS IMMUNE
SYSTEM NOT BENEFICIAL
Bacterial Septic Shock In Tuberculosis, MΦ Ingest MTB
But Cannot Digest It
Predominant Cytokines
Involved: IL-1 and TNF-α Eventually Burst - Releasing
Bacilli
Source: MΦ
MΦ And TH1 Cells Form
Intracellular Bacteria Cause
Granulomatous Lesion,
Granulomas
Containment+Destruction Of
Extensive Tissue Damage Healthy Tissue

Ex. Tuberculosis INF-γ and IL-12 Are Crucial In
Eliminating Pathogen


INFECTION BY VIRUSES
The Immune Response Against Virus Is Primarily Mediated Thru
Interferons

Double stranded RNA induces production of IFN

Main producers of IFNα and IFNβ are pDCs

TLR-3 (dsRNA); TLR-7 (ssRNA)

Interferons produce an anti-viral state

A state that inhibits viral replication

A state that inhibits viral infection

Antibody Protection Against Viruses
Antibodies Bind To Viral Surface Antigens

Protect against re-infection

Huge amounts of secretory IgA in lumen block viral attachment

Viral Entry Into Cells Is Mediated Thru Receptors

Inﬂuenza virus binds to sialic acid on glycoproteins

Rhinovirus binds to ICAMs

If Receptor Is Blocked, Infection Is Blocked

Oral Polio vaccine Relies On IgA Production

Antibody Protection Against
Viruses


Viruses

Antibodies Are Efﬁcient In Preventing Infection


Viruses


Once Infection Has Occurred, Only Cell Mediated
Immunity Can Eliminate Infected Cells


Viruses


Once Infection Has Occurred, Only Cell Mediated
Immunity Can Eliminate Infected Cells

Examples Of Cell Mediated Immunity

TH1, CTL Are the major participants


Viruses
TH1 Produce IFN-γ, IL-2,
and TNF-α

IL-2 expands CTL-P

IFN-γ induces antiviral
state

IL-2 and IFN-γ activate
NK cells (ﬁrst line of
defense)


Viruses
TH1 Produce IFN-γ, IL-2, CTL (cytotoxic
and TNF-α lymphocytes)

IL-2 expands CTL-P Peaks 7-10 days post
infection
IFN-γ induces antiviral
state Eliminate virally infected
cells
IL-2 and IFN-γ activate
NK cells (ﬁrst line of
defense)


VACCINES
& VPD


THERE ARE 2 WAYS TO PROTECT YOURSELF...
A.

B.


BACTERIAL VACCINES
Bacteria Disease Antigen Efficacy

Streptococcus Pneumonia Capsular 85%
pneumoniae polysaccharide
Neisseria meningitis Capsular 85%
meningitidis polysaccharide
Hemophilus meningitis Capsular 85%
inﬂuenzae polysaccharide
Corynebacterium Diphtheriae Toxoid >90%
diphtheriae
Clostridium tetani tetanus Toxoid >90%

Bordetella pertussis Whooping cough Killed organism >90%

Mycobacterium Tuberculosis Live attenuated 0 – 70 %
bovis (BCG)

Salmonella typhi Typhoid fever Killed/Live 80%
attenuated


IMMUNIZATION FOR INFANTS
Vaccine Reason for Immunization

BCG Given at the earliest possible age protects
against the possibility of infection from
family members

DPT Early start with DPT reduces chance of
severe pertussis

OPV Protection against polio increased the
earlier the OPV is given

Hepatitis B Early start of HBV vaccination reduces
chance of being infected and becoming a
carrier

Measles At least 80% of measles can be prevented
by immunization at this age


SCHEDULE
Age Diseases to be immunized against

Birth Tuberculosis

6 weeks DPT; Polio; HBV



9 months Measles


SIDE EFFECTS OF BCG
30 minutes  wheal SIDE EFFECTS:
disappears 1. Koch’s phenomenon- an acute
2 weeks: a small red inﬂammatory reaction
tender swelling 10 cm appearing within 2-4 days of
appears vaccination

3 weeks: swelling 2. Deep abscess at vaccination site
becomes a small – due to subcutaneous or
abscess which then deeper injection (I & D)
ulcerates
3. Indolent ulceration- an ulcer
12 weeks: course from which persists after 12 weeks or
vaccination to healing & > 10cm deep (Tx –INH powder)
scariﬁcation
4. Lymph node enlargement

SIDE EFFECTS DPT
SIDE EFFECTS: Advice/ Management
Fever: many children
develop fever after  Antipyretic or tepid sponge
injection , lasting only bath
one day; fever that
lasts more than 24  Reassure mother that
hours after a dose of
swelling needs no treatment
DPT is not due to the
and will disappear within
vaccine but to other
3-4 days
causes

Local Soreness: Pain or
swelling at injection
site


SIDE EFFECTS DPT
Abscess: If this appears a
week or more after the  Incision and drainage is
injection, it is due to necessary
wrong technique. Either
the vaccine was not  If convulsions occur, give
injected deep enough or
proper management and
the needed was not
do not continue the
sterile
normal course

Convulsions: Very rare;
occurs more in >3
months; usually due to
pertussis component of
the vaccine

SIDE EFFECTS MEASLES VACCINE
Fever and rash:
Children may develop Reassure the mother and
fever after 5-7 days advise antipyretic for
from the time of the child
vaccination

Fever lasts only from
1-3 days.
Sometimes a mild
rash appears


TETANUS TOXOID
Vaccine Minimum age/ Percent Duration of
protected
interval protection

As early as possible during
TT1 pregnancy

At least 4 weeks later * Infants born to the mother
TT2 80% protected from neonatal
tetanus; 3 years protection to
mother

At least 6 months later * Infants protected;
TT3 95% 5 years protection to mother

At least one year later * Infants protected;
TT4 99% 10 years protection to mother

At least one year later Lifetime protection for mother;
TT5 99% * all infants born to that mother
will be protected


VACCINES AND POLIO ERADICATION
EFFORTS (smallpox as model)

Parungao-Balolong 2011

MEASLES &
HERD
IMMUNITY

thepaltrysapien.com


EMERGING & RE-
EMERGING INFECTIONS


EMERGING & RE-EMERGING
INFECTIONS


PUBLIC HEALTH PLANNING
& INTERVENTION

Disaster and Outbreak Preparedness

Accessibility to Intervention and Good Clinical Management

Environmental Sanitation and Hygiene

Research: Diagnostics, Therapy and Pathogenic Mechanisms

Surveillance and Prevention Control Programs

Health Promotion and Awareness Ads and Campaigns


END OF BIO 120
LECTURES

Immunity and vaccines for exam 3

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