Whooping cough, also known as pertussis, is a highly contagious respiratory infection that can be fatal in infants. Here’s what you need to know.
Whooping cough, or pertussis, is on the rise again in the United States, and the number of cases in 2025 are nearly double what they were for this same period last year, according to the Centers for Disease Control and Prevention.
The CDC released numbers for pertussis cases up until April 26. There have been 9,034 cases reported in 2025 compared to 4,698 by this date in 2024.
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The CDC says that whooping cough is a very contagious respiratory illness that unlike a common cold can cause coughing for weeks or months.
The data shows that the state of Florida, where 468 cases have been reported, is also seeing this trend, with 27 just this week. At this same time last year, only 96 cases had been reported.
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In 2024, a total of 708 cases were recorded in the state, according to the Florida Department of Health.
The numbers for this year "are trending towards levels reported pre-pandemic in 2019," the Department of Health said. "Mitigation efforts used during the pandemic likely lowered transmission of pertussis."
In early April, a Weston elementary school warned parents that one case of whooping cough had been confirmed there. The health department then held a free voluntary vaccination event at the school.
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The best way to prevent whooping cough is to get vaccinated, the CDC says.
NBC News reported that whooping cough has been increasing since the early 2000s, according to Centers for Disease Control and Prevention data, with about 10,000 reported cases each year. The spread slowed during the pandemic lockdown, as many infectious illnesses did, but cases are rising once again.
A 2024 CDC report found that the percentage of U.S. kindergartners during the previous school year who had been vaccinated against both measles and whooping cough dipped to less than 93%. In 2019, the national coverage rate was 95%.
What's more, the pertussis vaccine doesn’t work as well as it used to. In the 1990s, manufacturers altered the way the vaccine was made to reduce its side effects, like fevers and vomiting. As a result, the shot’s effectiveness isn’t as robust. Boosters are needed every 10 years.
And research published by the CDC in 2019 suggested that the bacteria behind the disease had mutated. In 2024, the Food and Drug Administration met to discuss the need for more robust and longer-lasting versions of the whooping cough vaccine.
