Pertussis Vaccine Effectiveness declines Over Time

Pertussis or whooping cough is a contagious respiratory disease. Children are better protected after receiving a 5-dose vaccine series. A new study examined the relationship between pertussis and time since receipt of the fifth dose of the d-tap vaccination series. “Children with pertussis were less likely to have received the childhood pertussis vaccine series compared to children who did not have pertussis.”  Dr. Lara Misegades from the Centers for Disease Control and Prevention and co-authors reviewed vaccine histories for children four to 10 years old.  Researchers studied those with pertussis and compared them to children who did not and assessed whether a child completed the five dose series or was unvaccinated. “Within one year after having received the fifth dose of vaccine about 98% of children were protected against pertussis, when we moved out to five years about 70% of the children were protected. Protection fades over time.”  The study appears in the Journal of the American Medical Association.