Does the whooping cough vaccine shed and spread the disease? They do not “shed” the way live virus vaccines shed.
Pertussis is a bacteria, not a virus, and it is in acellular form which is why there's an "a" before the "P" in the name of the TDaP vaccine. It is chopped up bits of pertussis toxin (https://www.cdc.gov/mmwr/preview/mmwrhtml/00048610.htm) along with some other bacterial bits in the vaccine. The issue with DTaP and TDap is that they increase the risk of asymptomatic transmission because they tamp down symptoms but do not prevent the person from becoming infected with pertussis or from spreading it to others if they are exposed.
So although “scientists say people are protected from the disease if vaccinated” people vaccinated against pertussis can spread the disease to others.4 And this is precisely the point to bear in mind as you read about pertussis outbreaks.
The outbreaks are not necessarily occurring because of the lack of so-called “herd immunity”—not enough people being vaccinated. They may well be occurring because of the vaccinated population itself.
These acellular pertussis vaccines are also what’s called partial coverage vaccines. They only cover one strain of bacteria that causes whooping cough: Bordatella Pertussis. Because they only cover B. Pertussis, and because they have only EVER covered B. Pertussis, and because the number of DTaP and TDap vaccines given has increased so much over the years, Bordatella Parapertussis (one of the other strains) has now become much more prevalent than it used to be.
B. Parapertussis is now causing a significant percentage of the cases of whooping cough.
And... laboratory studies with primates show that those who are recently vaccinated with DTaP or TDap not only have ZERO PROTECTION from B. Parapertussis... the vaccine actually INCREASES the colonization of B.Parapertussis in the throat of recently vaccinated individuals by 40-fold.
Recently vaccinated individuals can not only get sick with pertussis, they may not have symptoms, and they can spread the infection to others without knowing it - AND, if exposed to B. Parapertussis, they are far more likely to become sick with whooping cough, and to spread it to others, than individuals who have not received the vaccine.
This article explains in detail, with the peer-reviewed citations:
This video explains in further detail