Whooping cough is surging in the United States, with cases now five times higher than they were at the same point last year, according to preliminary data from the US Centers for Disease Control and Prevention that was reported Friday.

In a report published Thursday, whooping cough cases were more than four times the amount at this time last year.

Infectious diseases experts say many Americans fell behind on their whooping cough vaccinations during the COVID-19 pandemic, which they say has compounded the recent uptick in cases.