"IgA anti-bodies to pertussis antigens are only produced after a natural infection and not after immuniza-tion."
If we but spend a little time thinking about this it may clear up MUCH about "vaccination" and why we should NEVER call "vaccination" "immunization". Only the natural process of naturally contracting the wild disease and NATURALLY acquiring the immune mechanisms to efficiently fight the WILD disease can produce human immunity to a wild disease.
Once a sufficient number of humans have acquired individual immunity to a wild disease a group of humans may acquire herd immunity to the wild disease.
"Vaccination" produces neither individual immunity to a wild disease NOR herd immunity to a wild disease.