Vaccines Flashcards
vaccine
substance designed to induce a potent and protective immune response to potential microbial pathogens by exposing the host to antigenic, non-pathogenic material (mimic as closely as possible without causing disease)
what is the purpose of immunization?
to prevent the multiplication of invading organisms, to neutralize their toxins, to prevent OR modify the disease process
active immunity
body’s response to exposure to a potential pathogen via immunization, natural infection, or exposure (hopefully leads to long-term protective response)
passive immunity
transfer of pre-formed antibodies to an individual; short-lived, does not induce memory
when do we passively immunize?
used when immediate protection is needed or the host cannot produce an adequate immune response (i.e. rabies virus, immune deficiency, RSV prevention in premature neonates, Rho-Gam)
inactivated vaccines: how are they made?
grow large numbers of virus or bacteria and kill them using hear or chemical fixation
live attenuated vaccines: how are they made?
produced by repeated passage of organism through cell culture or lab animals until a non-virulent strain of the organism is isolated (we make sure that they are stable enough that they won’t revert)
inactivated bacterial vaccines: functionality
limited, short-lived protection; not part of routine recommended vaccines in US
inactivated viral vaccines: functionality
may not produce as good or as long-lived protection (ex. Inactivataed influenza, rabies, Salk polio vaccine) but are safer for the immunocompromised
live attenuated viral vaccines: functionality
effective, generate long term protection, may need booster doses, antibody and CTL response, KNOW THESE: safety concern for select patients
live attenuated viral vaccines given in the US
measles, mumps, rubella, chickenpox, live oral influenza vaccine
how do you decide who can receive live attenuated vaccines?
for immunocompromised, must measure their CD4 cell count (need at least 15% CD4 to receive without risk)
purified antigen/subunit vaccines
only part of the virus, such as an inactivated toxin (diphtheria, tetanus) or purified polysaccharide antigen (more effective when coupled to protein=CONJUGATE)
give 2 examples of conjugate vaccines
prevnar13, Hib
synthetic/recombinant antigen vaccines
active part is a synthesized protein/AA sequence that has been shown to be an antigenic epitope
give an example of a synthetic/recombinant vaccine
Hepatitis B Vaccine
what are the adv/disadv of purified antigen/subunit vaccines as well as synthetic/recombinant vaccines?
very safe, but short shelf-life and failure to stimulate CTL response (exogenous antigens)
live viral vector vaccine
introduction of genes encoding microbial antigens into genome of non-cytopathic virus – safety concerns, but response is strong
DNA vaccines
inoculation of a plasmic containing a specific gene, plasmid DNA integrates into cell genome, inducing T and B cell response (but could induce tumorigenesis!)
additional substances added to a vaccine
adjuvants, diluents, stabilizers, antibiotics, preservatives
adjuvants
substances added to vaccine to improve or stimulate immune response (i.e. aluminum salts)
stabilizers
maintain viral potency (MSG, albumin, phenols, gelatin, glycine)
name two factors about an organism that decrease ability to develop an effective vaccine
diversity in surface structure; animal reservoirs
name one common vaccine used in the US where we still have a long way to go
pertussis
name 3 diseases that have been eradicated in the US due to vaccination
smallpox, diphtheria, polio
name a disease where the pediatric population is immune, but adults continue to get the disease
hepatitis B
are childhood immunizations cost effective?
VERY
benefits of immunization
personal immunity, herd immunity
herd immunity
when a certain percentage of a population is immunized, the microorganism cannot survive and even unimmunized are unlikely to come in contact with pathogen
risks of immunization
adverse reaction (local tenderness, mild systemic, rare allergic rxns)
how is vaccine safety monitored?
reporting systems, pharm companies required to perform surveillance for adverse events
is there any evidence that MMR or thimerosal can cause neurologic disease or autism?
NO
why do people think that these diseases are linked to vaccines?
genetic diseases tend to pop up around the same time that children are receiving lots of vaccines
