In a nutshell, the authors of the new pertussis study blame the apparent global resurgence of whooping cough cases on the failure of acellular pertussis vaccines, which were licensed for infants in the U.S. in 1996 after parents in Japan in the 1970s, and parents in the U.S. in the early 1980s, lobbied for a purified pertussis vaccine to cut down on the numbers of children being brain damaged and dying from DPT shots.
The authors allege that acellular pertussis vaccines, which demonstrated superior safety and effectiveness in prelicensure clinical trials conducted in the 1990s, do not work the way older whole cell pertussis vaccines did, and that it is this difference that is causing reported cases of whooping cough to increase. In 2014, there were more than 32,000 reported cases of whooping cough in the U.S., most of which occurred in vaccinated populations.
However, evidence shows pertussis deaths dropped by 75 percent between 1922 and 1948, a year before the introduction of DPT in 1949. In 1948, the mortality rate was less than 1 pertussis death per 100,000, and this rate has not been surpassed since. [5,6] So, the plummeting disease and mortality rates noted in the recently featured pertussis review were not the direct result of the whooping cough vaccine.
via Vaccine Impact Whooping Cough Outbreaks Traced Back to Vaccine Failure