Transcript Preparation of Vaccines

Making Vaccines
1.4.2
What makes an effective
vaccine?
Effective Vaccines
• Have low levels of side effects or toxicity.
• Protect against exposure to natural, or wild
forms of the pathogen.
Effective Vaccines
• Should stimulate both an
antibody (B-cell) response
and a cell mediated (Tcell) response.
• Have long term, lasting
effects that produce
immunological memory.
Effective Vaccines
• 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
Types of Vaccines
• 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, larger doses
and more boosters are
required.
Types of Vaccines
• Live, attenuated (weakened) cells or
viruses
– Vaccines are longer-lasting and require
fewer boosters
– However, the disease agent could
mutate back to pathogenic strain
Types of Vaccines
• Toxoid vaccines
–A purified toxin produced by the
antigen is used to elicit immune
response.
Types of Vaccines
• 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.
Types of Vaccines
• 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”.
Today
• 1.4.2 #2
• Visit the NOVA
website about
making vaccines.
• Take notes on the
steps.
• Answer conclusion
questions 1 and 2