Immunity and Vaccinations
Health Science
Objectives / Rationale
• The ability to develop immunity to diseases
is a key factor in maintaining health and
wellness.
• The student will learn the difference in
naturally acquired and artificially acquired
immunity and understand the importance of
vaccinations for individual and community
health.
• The Immune System is the
body’s special defense response
against foreign organisms.
Immune system includes:
• Lymphoid organs
– lymph nodes
– spleen
– thymus gland
• Their products –
– lymphocytes
– antibodies
Macrophages – phagocytes that are
found in the blood, brain, liver,
lymph nodes and spleen
*Immunity
• *The capacity to resist certain types
of organisms and toxins (poisons)
that will damage tissues and organs.
• *Natural (innate) Immunity – one’s
own ability to fight off disease. By
genetic predisposition, phagocytosis,
macrophages.
• *Acquired Immunity – the body
develops specific immunity
(antibodies and cells) against
invading agents such as lethal
bacteria, viruses, toxins, and even
foreign tissues from other organisms.
• *Acquired active immunity occurs in
two ways:
• By having a disease
• Receiving a vaccination containing a
modified pathogen or toxin, which
stimulates production of antibodies.
• Acquired passive immunity – the
patient receives immune serum
containing antibodies produced in
another animal.
• Examples: antitoxins, gamma globulin
White Blood Cells
• Protect us from infection, and help us
fight infection
• Neutrophils
• One of the body’s main defenses
against bacteria.
• Kill bacteria by actually ingesting them
(phagocytosis).
• Eosinophils – kill parasites and have a
role in allergic reactions
• Basophils – function in allergic
reactions. They release:
• histamine – causes blood vessels to
leak and attract WBCs, and
• heparin – prevents clotting in the
infected area so that the WBCs can
reach the bacteria.
• Lymphocytes – complex cells that
direct the body’s immune system.
• T lymphocytes – (T cells) – they
mature in the thymus and are
responsible for cell-mediated immunity
• Four types of T Lymphocytes:
• Helper T cells – direct the rest of the
immune system by releasing cytokines
which produce signals that regulate
cell growth and function during the
inflammatory response.
• Cytotoxic T cells – release chemicals
that break open and kill invaders.
• Memory T cells – remain afterwards to
help the immune system respond more
quickly if the same organism is
encountered again.
• Suppressor T cells – suppress immune
response so that it does not destroy
normal cells
• B Lymphocytes – responsible for
humoral immunity (antibody
production)
• Monocytes – called ‘wandering’ cells
until they enter a tissue where they
become fixed and turn into
macrophages.
• They destroy old, damaged and dead
cells in the body.
• Macrophages are found in the liver,
spleen, lungs, lymph nodes, skin and
intestine.
Naturally Acquired Immunity
• Active Immunity – immunity may be
acquired by exposure to a disease.
• *Antigen – a substance that triggers
an antibody response.
• An antigen can be anything from
bacteria to pollen; dust to drug; food to
animal.
• People are born with certain antigens,
such as those on the RBCs, depending
on their blood type.
• An antigen doesn’t produce an allergic
reaction in all people.
• Because…….
• In hypersensitive people, the presence
of an antigen combined with an
antibody provokes the release of
histamine which forms the basis for all
allergic symptoms.
• *Passive Immunity – immunity may
be acquired naturally by a fetus
through the passage of antibodies
from the mother through the placenta
or through breast milk to a nursing
infant.
• In this type of passive immunity,
antibodies come from an outside
source.
• These antibodies are temporary. They
will protect for up to 6 months or
longer if the mother continues nursing.
Artificially Acquired Immunity
• *Vaccination or
immunization – an agent is
introduced into the body to
stimulate antibody
production.
• Vaccine is given by injection or liquid
by mouth.
• Needle free: inhalation of aerosol or
powder.
• The body makes antibodies against the
weakened or killed pathogens from the
vaccine.
• These antibodies can fight the
pathogens when they invade the body.
The antibodies destroy them and the
person will not become ill.
• Protective antibodies then stay on
guard in the body to safeguard it from
the real disease if the person ever
becomes exposed to the real disease.
This protection is immunity.
Vaccines
• Live organisms – must be nonvirulent
for humans or treated in the lab to
weaken them so that are not as
pathogenic to humans.
• Attenuated – an organism that has been
weakened.
• Killed – vaccination with a toxoid
occurs when the toxin produced by an
organism is altered with heat or
chemicals to render it harmless, but
still allows the body to make
antibodies against it.
*Examples of Vaccines
• *Anthrax – a serious disease that can
affect both animals and humans.
• Contracted from infected animals,
wool, meat, or hides
• Causes skin ulcers, fever, fatigue.
• 20% of the cases are fatal
• Inhaled anthrax is more serious.
• Anthrax vaccine protects against both
types of anthrax.
• Who should be vaccinated? Those 1865 y/o potentially exposed to large
amounts of the virus – lab workers,
military personnel at risk.
• Three doses given at 2 week intervals.
• Three additional doses each six months
after the previous dose. Boosters.
• *DPT – Diptheria, Tetanus,
Pertussis
• Diptheria – causes a thick covering on
the back of throat, can lead to
breathing problems, paralysis, heart
failure and death.
• Tetanus – causes painful tightening of
muscles, leading to “lockjaw” – cannot
open mouth or swallow; leads to death
in 1 out of 10 cases.
• *Pertussis (whooping cough) – causes
coughing spells so bad it is hard to eat,
drink, breathe. Can lead to pneumonia,
seizures, brain damage, death.
• Children should receive 5 doses of the
DtaP vaccine.
• Mild risks and serious risks involved.
• *Hemophilus Influenza, Type b
(Hib)
• Serious disease caused by a bacteria.
• Hib is spread person-to-person.
• If it remains in nose and throat, the
person will not get sick.
• If it moves to the lungs or blood
stream, can be serious.
• *Hepatitis A Vaccine –
• Hepatitis A is a serious liver disease
caused by Hep A virus, found in stool
of persons with Hep A.
• Can be spread by close personal
contact or by eating food or drinking
water contaminated by it.
• Causes mild flu-like illness, jaundice,
stomach pain, diarrhea.
• Hep A vaccine should be given in 2
doses at least 2 months apart.
• Who should get? Travelers to or
residents of countries with high rates of
Hep A – 1 month before traveling;
homosexual men; street drug users;
individuals with chronic liver disease.
• *Hepatitis B Vaccine –
• Hep B (HBV) is serious. Can cause
acute or chronic illness.
• 1.25 million people in U.S. have
chronic HBV. Each year, it is
estimated that 80,000 people, mostly
young adults will get it; 4000-5000
people will die each year.
• HBV is spread through contact with
blood and body fluids of an infected
person: having unprotected sex,
sharing needles, being stuck with an
infected needle, during birth when
passed from mother to baby.
• Who should get? those 18 y/o and
younger. High risk adults.
• Three doses
• *Influenza Vaccine –
• Influenza is caused by a virus; spreads
form infected persons to nose or throat
of others. Usually Nov through April.
• Causes fever, cough, chills, sore throat,
headache, muscle aches.
• Causes thousands of deaths annually.
• The virus changes often.
• Let’s look at a Brainpop video on flu.
• *Lyme Disease Vaccine – Lyme
disease is caused from being bitten by
an infected tick.
• Common sign is a round, red,
expanding rash 2 inches or more in
diameter btw 3 days and a month after
the tick bite. Fever, chills, headaches,
joint and muscle pain can also occur.
• Can lead to arthritis, heart rhythm prob
• *Measles, Mumps, Rubella (MMR) –
• Measles virus causes rash, cough,
runny nose, eye irritation, fever.
• Mumps causes fever, headache &
swollen glands and can lead to
deafness, meningitis, painful swelling
of testicles or ovaries, death.
• Rubella (German Measles) causes rash,
mild fever, arthritis.
• If a woman gets rubella while
pregnant, she could miscarry, or her
baby could be born with serious birth
defects.
• Who should get the MMR vaccine?
• Children (2 doses)
• Adults born after 1956
• *Meningococcal vaccine –
meningococcal disease is a serious
illness caused by a bacteria; is the
leading cause of bacterial meningitis.
• Is an infection of the brain and spinal
cord covering.
• Who should get?
• U.S. Military recruits
• People exposed during an outbreak
• Travelers to a country where it is
common
• Anyone who has a damaged or
removed spleen
• Lab workers routinely exposed to the
bacteria
• College students living in a dorm
• *Polio vaccine – polio is a disease
caused by a virus that enters through
the mouth and can cause paralysis and
death.
• No “wild” polio has been reported in
the U.S. for > 20 years. Still common
in some parts of the world.
• *Smallpox – last natural case of
smallpox occurred in 1977, and in
1980, the World Health Organization
(WHO) declared the global eradication
of smallpox and recommended that all
countries cease vaccination.
• Because of concerns that the virus
could be used as a bioterrorism
weapon, the CDC has a plan.
• The plan will coordinate CDC, state,
and local public health activities if an
outbreak occurs, and it will help health
officials define and control the
outbreak.
• This includes indications for
vaccination, contraindications for
vaccination, risks, sites, personnel,
facilities, etc.
• *Tetanus and Diptheria Vaccine –
(Td) – Tetanus is caused by a germ that
enters the body through a cut or
wound. Diptheria spreads from person
to person.
• People get the original vaccination
after 7 y/o. Should also get one every
10 years throughout their life.
• *Varicella (chickenpox) vaccine – the
virus can spread from person to person
through the air, or by contact with fluid
from the blisters.
• A person who has had chickenpox can
get a painful rash – herpes zoster
(shingles) – later in life.
• With any vaccine, there are risks and
contraindications.
• Each person should be evaluated as to
which vaccines they should or should
not receive.
• Immunity may not be life-long with
vaccines. Sometimes, booster shots
are needed to keep antibody levels high
enough for protection.