關於antibodies!~(F.5 biology)

when u are invaded by the same pathogen again. Same antibodies will be produced ,but the concentration of antibodies produced will be more than that in the first attack.(due to the memory of lymphocytes)
there is a immunity level for the concentration of antibodies. if the concentration of the antibodyies are higher than that level, we can resist the same pathogen forever.
if the concentration of antibodies is still lower than the immunity level, we may still feel sick . ( the point is that whether the concentration of antibodies is over the level or not )
for example, if we are attacked for three times, but the concentration of that kind of antibodies is still lower than the immunity level, we cannot resist the pathogen.
but maybe in fourth time, the concentration increses more and is over the immunity level, u are able to resist the same pathogen forever.

你種左卡介苗,會否再患肺結核?這當然不會.
原理等同注射疫苗,打左D pathogen落身體裡面,
some of the lymphocytes can memorize the antigen on the pathogen.
係second infection 時, body 就會因應 d pathogen 去 produce antibodies.