Originally posted by squiz
Case in point--- the very first vaccine, smallpox over 150 years ago is not the darling that we were led to believe eradicated smallpox.
They didn't understand much about the importance of a weakened innoculant back then. They tried to innoculate with an already virulent agent and instead of innoculating they were infecting.
Things got better when they started using the cowpox virus instesd of small pox virus. It gave some protection that allowed people to survive smallpox in larger numbers by giving some degree of resistance to a similar strain.
The problem with many vaccines is not the inocculatory virus in its self but the adjuncts that are used to contain it or a poor choice of innoculant to begin with.
[edit on 17-11-2009 by badgerprints]