VACCINES VACCINES What They Are What They Are How How They They Work Work Topics in nanobiotechnology Ph.D. Student: Aleksandra Różek Ph.D. Student: Aleksandra Różek
Dec 28, 2015
VACCINESVACCINESWhat They Are What They Are HowHow They They WorkWork
Topics in nanobiotechnologyPh.D. Student: Aleksandra RóżekPh.D. Student: Aleksandra Różek
What Is a Vaccine?What Is a Vaccine?
Traditional vaccines contain either parts of microbes or whole microbes that have been killed or weakened so that they don’t cause the disease.
- take advantage of the body’s to learn how to eliminate almost any disease causing germ, or microbe,
that attacks it.
Immune system takes > 1 week to learn how to fight off an unfamiliar microbe.
Stronger microbes can spread through the body faster than the immune system can fend them off.
VaccineVaccine Benefits Benefits
Naturally acquired immunityNaturally acquired immunity – – immunity produced by immunity produced by antibodies passed from mother to fetus (passive), or by the body’s own antibodies passed from mother to fetus (passive), or by the body’s own antibody and cellular immune response to a disease causing organism antibody and cellular immune response to a disease causing organism (active).(active).
Artificially acquired immunityArtificially acquired immunity – – immunity provided by vaccines, as opposed to naturally acquired immunity, which is acquired from exposure to a disease-causing organism.
Herd immunityimmunity –– the resistance to a particular disease gained the resistance to a particular disease gained by a community when a critical number of people are vaccinated by a community when a critical number of people are vaccinated against that disease.against that disease.
How Vaccines Work?How Vaccines Work?
Immune systemImmune system – – a collection of specialized cells and organs that protect the body a collection of specialized cells and organs that protect the body
against infectious diseases.against infectious diseases.
LymphocytesLymphocytes: T : T CellsCells & B & B CellsCells
Lymphocytes - Lymphocytes - white blood cells that are central to the immune system’s white blood cells that are central to the immune system’s response to foreign microbes.response to foreign microbes.
MacrophagesMacrophages – large and versatile immune cells that devour and – large and versatile immune cells that devour and kill invading microbes and other intruders. kill invading microbes and other intruders.
- stimulate other immune cells by presenting them with small pieces - stimulate other immune cells by presenting them with small pieces of the invaders.of the invaders.
B Cells – white blood cells crucial to the immune defenses. They come from bone marrow and develop into blood cells called plasma cells, which are the B Cells – white blood cells crucial to the immune defenses. They come from bone marrow and develop into blood cells called plasma cells, which are the source of antibodies.source of antibodies.
T Cells – white blood cells that direct or participate in immune defenses.T Cells – white blood cells that direct or participate in immune defenses.
Memory Cells and natural immunityMemory Cells and natural immunity
After body eliminated the disease some of the B cells and T cells are converted into memory cells.
Memory B cells can quickly divide into plasma cells and make more antibody if needed.
Memory T cells can divide and grow into disease-fighting army.
Different Types of VaccinesDifferent Types of VaccinesLive, attenuated vaccineLive, attenuated vacciness
A vaccine made from microbesA vaccine made from microbes
that have been weakened in thethat have been weakened in the
laboratory so that they can’t causelaboratory so that they can’t cause
disease.disease.
Disease:Disease:Measles, mumps, rubella, polioMeasles, mumps, rubella, polio
(Sabin vaccine), yellow fever(Sabin vaccine), yellow fever
Inactivated or „killed” vaccinesInactivated or „killed” vaccinesA vaccine made from a whole viruses or bacteriaA vaccine made from a whole viruses or bacteria
tthat has been inactivated with chemicals or heat.hat has been inactivated with chemicals or heat.
Disease:Disease:Cholera, flu, hepatitis A, JapaneseCholera, flu, hepatitis A, Japanese
eencephalitis, plague, polio (Salk Vaccine), rabiesncephalitis, plague, polio (Salk Vaccine), rabies
Toxoid vaccineToxoid vaccineA vaccine containing a toxoid, used to protectA vaccine containing a toxoid, used to protect
aagainst toxins produced by certain bacteria.gainst toxins produced by certain bacteria.
Disease:Disease:Diphtheria, tetanusDiphtheria, tetanus
Subunit vaccineSubunit vaccinessA vaccine that uses one or more componentsA vaccine that uses one or more components
oof a disease – causing organism, rather thanf a disease – causing organism, rather than
tthe whole, to stimulate an immune responsehe whole, to stimulate an immune response..
Disease:Disease:Hepatitis B, pertussis, pneumonia caused byHepatitis B, pertussis, pneumonia caused by
Streptococcus pneumoniaeStreptococcus pneumoniae
Different Types of VaccinesDifferent Types of VaccinesConjugate vaccinesConjugate vaccines
A vaccine in which proteins that are easily recognizableA vaccine in which proteins that are easily recognizable
to the immune system are linked to the molecules thatto the immune system are linked to the molecules that
form the outer coat of disease – causing bacteria to form the outer coat of disease – causing bacteria to
promote an immune response. Conjugate vaccines are promote an immune response. Conjugate vaccines are
designed primarily for very young children because theirdesigned primarily for very young children because their
immune systems can’t recognize the outer coats of certain immune systems can’t recognize the outer coats of certain
bacteria.bacteria.
Disease:Disease:Haemophilus influenzae type B, pneumoniaHaemophilus influenzae type B, pneumonia
Caused by Streptococcus pneumoniaeCaused by Streptococcus pneumoniae
DNADNA vaccine vaccinessA vaccine that uses a microbe’s genetic material,A vaccine that uses a microbe’s genetic material,
rather than the whole organism or its parts, to stimulaterather than the whole organism or its parts, to stimulate
an immune response.an immune response.
Disease:Disease:In clinical testingIn clinical testing
Recombinat vector vaccinesRecombinat vector vaccinesVaccines that use modified viruses or bacteria to deliverVaccines that use modified viruses or bacteria to deliver
ggenesenes that code for microbial antigens to cells of the body. that code for microbial antigens to cells of the body.
Disease:Disease:In clinical testingIn clinical testing
Produce a strong immune responseProduce a strong immune response
Often give livelong immunity with one or two dosesOften give livelong immunity with one or two doses
Safer and more stable than live vaccinesSafer and more stable than live vaccines
Don’t require refrigeration: more easily stored andDon’t require refrigeration: more easily stored and
transported transported
Teaches the immune system to fight off bacterial Teaches the immune system to fight off bacterial toxinstoxins
Targeted to very specific parts of the microbeTargeted to very specific parts of the microbe
Fewer antigens, so lower chance of adverse reactionsFewer antigens, so lower chance of adverse reactions
Allow infant immune systems to recognize certain Allow infant immune systems to recognize certain bacteriabacteria
Produce a Produce a strongstrong antibody and cellular immune antibody and cellular immune responseresponse
Relatively easy and inexpensive to produceRelatively easy and inexpensive to produce
Closely mimic a natural infection, stimulating a Closely mimic a natural infection, stimulating a strong immune responsestrong immune response
Remote possibility that the live microbe could mutate back to Remote possibility that the live microbe could mutate back to a virulent forma virulent form
Must be refrigerated to stay potentMust be refrigerated to stay potent
Produce a weaker immune response than live vaccinesProduce a weaker immune response than live vaccines
Usually require additional doses, or booster shotsUsually require additional doses, or booster shots
When developing a new vaccine, identifying the best antigens When developing a new vaccine, identifying the best antigens can be difficult and time consumingcan be difficult and time consuming
Still in expertimental stagesStill in expertimental stages
Still in expertimental stagesStill in expertimental stages
AdvantagesAdvantages DisadvantagesDisadvantages
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