Here's just one article to get you started-
Whooping Cough Bacteria Has Mutated, Vaccines No Longer Effective
Posted by Amber Robinson at 11:11 AM on February 11, 2010
Dramatic increases in the incidence of whooping cough in Australia had been put down to an increase in non-vaxers. But new research indicates that it might not be non vaccinating parents who caused the spike, but the vaccination itself.
Significant changes in the two most common strains of the bordetella pertussis bacteria (which causes whooping cough) have been detected, and researchers have named a change in the type of vaccination as a cause for the bacteria mutation.
Australian children were given a broad-acting whole cell vaccination against whooping cough (also known as pertussis) up to 1997, but this then phased out and replaced with a more targeted version which was thought to have fewer side effects.
While the whole cell vaccine contained hundreds of antigens, which gave broad protection against many strains of pertussis, the (targeted) acellular vaccine contains only three to five antigens.
Researchers think that the use of the acellular vaccine may be one factor contributing to the genetic changes in the bacteria.
this was taken from a magazine, not a credible source.
Like I said, it was just one article to get you started. Keep researching it.
The article linked to a CDC document that says the following:
The reemergence of pertussis has been attributed to
various factors, including increased awareness, improved
diagnostics, decreased vaccination coverage, suboptimal
vaccines, waning vaccine-induced immunity, and pathogen
adaptation. The relative contribution of these factors may
differ between countries and is the subject of ongoing debate.
Here is the CDC article in full... it got too scientific for me to understand, lol
https://www.cdc.gov/eid/content/15/8/pdfs/1206.pdf
It did go on to study the variation in the strain of the disease and came to this conclusion:
The effect of pathogen adaptation on disease impact
may depend on factors such as vaccine coverage and the
quality of the vaccine used, which may differ between
countries. A relatively weak vaccine used in the Netherlands
may have exacerbated the effect of the emergence of
ptxP3 strains on disease impact
and:
Pertussis among recently
vaccinated children is rare, indicating that pathogen adaptation
does not play a role unless immunity has waned.
My conclusion upon reading this? Vaccinating young children is still extremely important as it will protect them from the disease at a point where they are most vulnerable. There was no indication from what I read that young children who had been vaccinated were catching this new strain.
Waning protection is because people do not receive their booster shots (I got my booster shot 3 years ago in combo with my Tetanus booster). So continuing to get booster shots even when the disease is no longer so dangerous to you as you reach adulthood may still carry benefits to the general population of helping to prevent the spread and creation of a pathogen adaptation.