vaccines and vaccinology Flashcards
jenner
1796- infected gardeners son with cowpox- son was immune to smallpox
vaccines used today
human, domesticated livestock, pets, fish and wild animals
three diseases that have been reduced considerably due to vaccine
diphtheria, polio and measle
how many lives saved in past 20 years
20 million
how many live saved i 2003
2.5
what is an example of an eradicated disease
smallpox- once killed 5 mill/yr
how many additional lives a year could be saved by extending vaccine programmes to all countries
2 mill
infectious disease that don’t have vaccines available
malaria, schistosomiasis, tuberculosis, meliondosis, respiratory disease, diarrhoea disease, HIV and aids
infection has 2 possible outcomes
recovery and resistance or death
not all infections mean
resistance to reinfection
if an infection allows natural immunity
then feasible to devise a vaccine e.g. polio, smallpox, influenza, plague, anthrax, pertussis
if not resistant to reinfection
diff or impossible to devise a vaccine e.g. HIV, malaria, tb, schistosomiasis, gonorrhoeae
vaccines mimic
the natural disease- they trick the body into thinking that it has been infected - but can only work if the body can generate a protective esponse
protective response
antibodies and cellular immunity
antibodies
proteins that circulate in the blood, binding to toxins, viruses or bacteria. Neutralising and promoting clearance of infection- produced by B cells
Cellular immunity involving T cells
CD4+ T cell: orchestrate the immune response
CD*+ T cells: kill infected cells
types of vaccine
live, killed, subunit and naked DNA vaccines
live vaccines
living but cannot cause disease
killed vaccine
killed by heating, or exposure to chemicals
subunit vaccines
fragment of the microorganism e.g. proteins or polysaccharides