In the 1990’s, the US replaced whole cell pertussis vaccines
with acellular pertussis vaccines over safety concerns. A research letter to Journal of the American Medical Association
reports that the switch might be responsible for a recent rising number of pertussis cases
(whooping cough) in children. Compared with whole cell vaccines, acellular vaccines resulted in approximately a 600% increase in incidence rate of pertussis looking at reporting rates in Australian children between 1999 and 2011. The researchers conclude that “possible explanations for our findings could include antigenic shifts in circulating Bordetella pertussis
or the different immune responses from acellular and whole-cell priming.”
Read it in JAMA.