Transcript Preparation of Vaccines

Making Vaccines
Effective Vaccines
• Have low levels of side effects or toxicity.
• Protect against exposure to natural, or wild
forms of the pathogen.
• Should stimulate both an antibody (B-cell)
response and a cell mediated (T-cell) response.
• Have long term, lasting effects that produce
immunological memory.
• Should not require numerous doses or boosters
• Are inexpensive, have a long shelf life and are
easy to administer.
Routes of Administration
• The majority of
vaccines are
administered by
injection
– Subcutaneous
– Intramuscular
– Intradermal
• Oral vaccines are
available for only a
few diseases
Administration Routes
Live, attenuated (weakened)
cells (viruses)
– Vaccines are longer-lasting
and require fewer boosters
– However, the disease agent
could mutate back to
pathogenic strain
– Harder to make this type for
bacteria – usu. viruses
– Example: MMR, Varicella
zoster
Killed whole cells or inactivated
viruses
– Even though they are
harmless, they still contain
recognizable antigens on
their surface
– Because the microbe does
not multiply, a weaker
immune response is
stimulated vs. live vaccines
– larger doses and more
boosters are required.
– Example:Polio virus
Toxoid vaccines
– A purified
toxin
produced by
the antigen is
used to elicit
immune
response.
– Example:
DTaP
• Diptheria,
Tetanus and
acellular
Pertussis
Subunit Vaccines
• Subunit vaccines contain
just the antigens of the
microbe that best stimulate
the immune system.
• Antigens that have been
separated from the rest of
the microbe
• Examples: Hepatitis B,
Gardasil, Influenza
Genetically engineered
microbes or microbial antigens
– Genes for microbial antigens are inserted into a
plasmid vector and are cloned in appropriate hosts.
– The resultant protein product is used to provoke
immune system.
DNA vaccines
– These
vaccines
contain
all or part
of the
pathogen
DNA,
which is
used to
“infect” a
recipient’
s cells.
Herd Immunity
• More individuals that are
immune decreases the
incidence of the disease and
the occurrence of the
pathogen.
• With greater numbers
immunized, it is less likely that
an unimmunized person will
encounter the pathogen.
• Mass vaccination confers
indirect protection for those
who do not receive the
vaccine resulting in “herd
immunity”.