Transcript Principles of Vaccination Epidemiology and Prevention of Vaccine

Principles of Vaccination
Epidemiology and Prevention of VaccinePreventable Diseases
National Center for Immunization and
Respiratory Diseases
Centers for Disease Control and Prevention
Revised April 2009
Diphtheria
Tetanus
Whooping cought
Meningitis – Hib,
Streptococcus, Neisseria
Measels
Poliomyelitis
Iron lung – after poliomyelitis
Jenner, Variolisation,
Ramses, eradication
Principles of Vaccination
Immunity
• Self vs. nonself
• Protection from infectious disease
• Usually indicated by the presence
of antibody
• Very specific to a single organism
Principles of Vaccination
Active Immunity
• Protection produced by the person's
•
own immune system
Usually permanent
Passive Immunity
• Protection transferred from another
•
person or animal
Temporary protection that wanes
with time
Way to get immunised
actively
Aktívna imunita
Pasívna imunita
passively
transplacentarly
disease
Prirodzene získaná
Prirodzene získaná
Naturally
vaccination
immunisation
immunotherapy
immune sera
Umelo navodená
Umelo
Artificially
navodená
Stávame sa imúnnymi prirodzenou cestou alebo umelo. Očkovaním si vytvárame
umelo získanú aktívnu imunitu voči chorobám.
Principles of Vaccination
Antigen
• A live or inactivated substance
(e.g., protein, polysaccharide)
capable of producing an immune
response
Antibody
• Protein molecules (immunoglobulin) produced by B
lymphocytes to help eliminate an
antigen
Protilátky
Antigény
Epitopy
Protilátky produkované bunkami imunitného systému rozpoznávajú cudzie antigény –
ich charakteristické molekuly – antigénne determinanty - epitopy
Passive Immunity
• Transfer of antibody produced by
one human or other animal to
another
• Temporary protection
• Transplacental most important
source in infancy
Sources of Passive Immunity
• Almost all blood or blood
products
• Homologous pooled human
antibody (immune globulin)
• Homologous human
hyperimmune globulin
• Heterologous hyperimmune
serum (antitoxin)
Monoclonal Antibody
• Derived from a single type, or
clone, of antibody-producing cells
(B cells)
• Antibody is specific to a single
antigen or closely related group of
antigens
• Used for diagnosis and therapy of
certain cancers and autoimmune
and infectious diseases
Vaccination
• Active immunity produced by
vaccine
• Immunity and immunologic
memory similar to natural
infection but without risk of
disease
Classification of Vaccines
• Live attenuated
– viral
– bacterial
• Inactivated
Inactivated Vaccines
Whole
• viruses
• bacteria
Fractional
• protein-based
– toxoid
– subunit
• polysaccharide-based
– pure
– conjugate
Principles of Vaccination
General Rule
The more similar a vaccine is to
the disease-causing form of the
organism, the better the
immune response to the
vaccine
Live Attenuated Vaccines
• Attenuated (weakened) form of
the "wild" virus or bacterium
• Must replicate to be effective
• Immune response similar to
natural infection
• Usually produce immunity with
one dose*
*except those administered orally
Live Attenuated Vaccines
• Severe reactions possible
• Interference from circulating
antibody
• Fragile – must be stored and
handled carefully
Live Attenuated Vaccines
• Viral
• Bacterial
measles, mumps,
rubella, varicella/zoster,
yellow fever, rotavirus,
intranasal influenza,
rotavirus, vaccinia
BCG, oral typhoid
Inactivated Vaccines
• Cannot replicate
• Generally not as effective as live
•
•
•
•
vaccines
Less interference from circulating
antibody than live vaccines
Generally require 3-5 doses
Immune response mostly humoral
Antibody titer may diminish with time
Inactivated Vaccines
Whole-cell vaccines
• Viral
• Bacterial
polio, hepatitis A,
rabies, influenza*
pertussis*, typhoid*
cholera*, plague*
*not available in the United States
Inactivated Vaccines
Fractional vaccines
• Subunit
• Toxoid
hepatitis B, influenza,
acellular pertussis,
human papillomavirus,
anthrax
diphtheria, tetanus
Pure Polysaccharide Vaccines
• Not consistently immunogenic in
children younger than 2 years of
age
• No booster response
• Antibody with less functional
activity
• Immunogenicity improved by
conjugation
Polysaccharide Vaccines
Pure polysaccharide
• pneumococcal
• meningococcal
• Salmonella Typhi (Vi)
Conjugate polysaccharide
• Haemophilus influenzae type b
• pneumococcal
• meningococcal
Future of vaccine
• Antiidiotype vaccines, DNA vaccines,
• One, not hurting, for everybody,
immunogenic, not harming, protecting
against all diseases, only one
disadvantage = not real
• Multivalent vaccines – more
immunogenic
Fases of new vaccines
development – laboratory,
preclinical
Field, clinical study
Skôr ako je vakcíne udelená licencia, prebieha testovanie jej bezpečnosti a stanovenie
účinnosti u dobrovoľníkov v niekoľkých fázach s presne stanovenými podmienkami
Risks of immunisation
• Side effects on any part of vaccine redness, indurance, ache, fever, cry,
alergy
• Immunisation – small regulated
infection - mild reaction, not target
tissue infection
• Not real expectances
Population immunity
• Collectove immunity – more than 85%
vaccinated against infection spread
from 1 to the other
• Protection of not immunisable or not
immunised „herd effect“
• Not present for tetanus, rabies
Surveillance a immunological
surveys
• Surveillance – system of epidemiological
patrolling
• Immunological surveys – targeted
sampling of sera from different age
groups to find not protected groups, to
organise aimed vaccination - mopping,
or catch up vaccination or changes of
immunisation schedule
Decrease of morbidity for DTP
after introduction of DTP
vaccination
INCIDENCE of HIb MENINGITIS - decrease
influenced by the amount of applicated
vaccines
20
15
10
všetky
5
0 rokov
1- 4 rokov
0
1
2
5 ´00
6
7
´94 ´95 ´96
´97 3 ´984 ´99
´01 8
´02
200 000
150 000
100 000
50 000
0
1
9
Antivaccination activity
• Vaccination mostly in child population
• very sesitive topic, period of discovery of
•
•
•
•
many diseases and handicapes in children
demagogical arguments,
not causal connection,
medialisation, not medically graduated
people, usually educated in other vague
topics – ecology, homeopathy.....
Dangerous – more people affected by
vaccination preventable diseases in USA
and Germany then for bioterroristic threat
Kontraindikácie očkovania
• Akútne ochorenie, horúčka
• Individuálne u pacientov s neurologickým
postihutím, predchádzajúcou reakciou na
očkovanie
• Nepodávať živú OL tehotným alebo
•
imunosuprimovaným (BCG?)
Jasne vyhodnotiť riziko očkovania a jeho
odmietnutia