Abstract
Background:Hypotonic-hyporesponsive episode (HHE) after whole cell pertussis vaccination is a known adverse event. Less is known about the risk of HHE after administration of acellular pertussis vaccines.Methods:Using parental interviews, this study actively surveyed for HHE among infants after doses 1 and 2 of acellular pertussis vaccine.Results:We interviewed the parents of 52,531 infants. HHE was reported at a rate of 22.8 per 100,000 doses (95% CI: 11.8–39.9) of acellular pertussis vaccine, approximately 45 episodes per 100,000 children.Conclusions:These rates are lower than HHE rates reported after whole cell pertussis vaccines and within the range of HHE rates reported in other studies of acellular pertussis vaccines.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
