Whooping Cough Cases Surge to Record Levels Across North America

Experts point to waning vaccine efficacy and unpredictable outbreak patterns as key factors driving the increase.

The U.S. has reported 14,569 whooping cough cases this year, a fivefold increase from the same period last year.
Ontario is on track to exceed its highest case count since 2012, with 1,016 cases reported as of September 9.
Quebec has seen a decline in weekly cases but remains the hardest-hit province in Canada with 13,716 cases this year.
Experts attribute the rise in cases to the waning efficacy of current vaccines and potential bacterial mutations.
Human challenge trials are being considered to speed up the development of more effective and longer-lasting vaccines.