vaccination Flashcards
what is difference between primary and secondary immune responses
primary response is fairly week and short lived
secondary response is much stronger and long lasting
primary response generates memory cells, secondary response uses memory cells
what is mechanism for vaccinations
used for specific pathogens and create immune memory
work on B cells producing antibodies, cytotoxic T lymphocytes and T helper cells
what may be sources of antigen for vaccination
source of antigen: attenuated organism (modified organism without virilance), dead organism, subunits (protein/polysaccharide), inactivated toxin/toxoid (e.g tetanus)
what is contained in a vaccine
vaccine components: antigen source, carrier (provides helper T-cell epitopes), adjuvant
what are adjuvants
adjuvants are added to vaccines to increase the chance (make sure) of immune response, activates APCs in non specific way
what are problems with vaccines
immunocomprimised hosts may be infected, vaccines often used from chicken eggs; vegans, older people may have problems with vaccines
what are requirements for a successful vaccine
creates appropriate adaptive response, produces antibodies and or cytotoxic T lymphocytes
readily available in region of use (e.g africa)
stable for transportation
inexpensive
safe (lack of side affects )
long shelf life
requires only 1 dose
what are pathogens that have been eradicated by vaccines
smallpox, rinderpest (cattle)
what is difference between antigenic shift and antigenic drift
antigenic shift and drift: antigenic drift (single point in DNA mutates), antigenic shift (large amounts of DNA swap/change causing completely altered protein)
how is influenza vaccinated against
influenza mutates rapidly and so is hard to vaccinate against
both shift and drift occur in influenza
main antigenic proteins in influenza: neuraminidase, hemagglutinin
flu vaccine for next year determined by “educated guesses”, by trying to predict what mutations will happen
what is main complication of HIV vaccine
identification of immunogens and immunisation strategy that induces broad and long lasting cytotoxic T cell immunity, and broadly neutralising antibodies
what is a conjugate vaccine
a vaccine thats conjugated to a protein carrier to make it more attractive to immune system e.g; conjugation of polysaccharide capsule with tetanus or diptheria toxoid (converts response from T-independent to T dependent)
what are vaccines recommended for people over 60
influenza, pneumococcal, tetanus, VZV (shingles)
what is inflammaging
low grade chronic systemic inflammatory state
strong predictor of frailty and mortality
increased systemic levels of IL-6, TNFalpha and C-reactive protein (CRP)
in ageing all immune compartments will be effected
how is vaccine response effected by age
problems associated with decreased vaccine response associated with immune senescence
the older you are the lower the likelihood of an immune response occuring to a vaccine as well as strength of response (amount of antibody produced), decreased immune and vaccine responses in old people
what is benefit of large scale vaccination
often protective immunity is not achieved in a large proportion of the population, however disease severity may be reduced
