As the United States grapples with rising measles cases and outbreaks in several states, another vaccine-preventable disease is quietly spreading throughout the country.
This year, there have been at least 7,599 cases of pertussis, also known as whooping cough, up from 3,473 cases at this time last year, according to the latest tally by the Centers for Disease Control and Prevention. With a record number of parents seeking vaccine exemptions for their children and childhood vaccination rates declining, more outbreaks of measles, pertussis, and other diseases are not just likely, they’re inevitable.
“When vaccination rates fall, the first disease you’re going to see show up is measles because it’s so contagious, but others will follow,” says Ari Brown, a pediatrician in Texas, the epicenter of the current measles outbreak, and a spokesperson for the American Academy of Pediatrics. “This is a troublesome trend.”
Last year, there were 285 cases of measles for all of 2024. This year, cases have already risen to over 700, and two children have died of the disease. Children have also been dying of whooping cough. In Louisiana, two infants died of the disease in the past six months—the state’s first deaths from the illness since 2018—according to a recent statement by the state’s surgeon general. In January, South Dakota’s department of health announced that a child died due to a co-infection of flu and pertussis. And in February, a local health department in Washington confirmed that a Spokane County child under the age of 5 died of whooping cough—the first in the state since 2011.
A type of bacterial infection, whooping cough is spread through respiratory droplets when an infected person coughs or sneezes. It causes flu-like symptoms and violent, rapid coughing. It’s known for the characteristic, high-pitched “whoop” sound when someone inhales after a coughing fit. The disease is especially dangerous for babies because it can interfere with their breathing.
Nationwide, there were 35,435 cases of whooping cough in 2024, compared with 7,063 in 2023, according to a provisional surveillance report from the CDC. Cases hit a low of 2,116 in 2021 due to social distancing during the Covid-19 pandemic and were still on the rebound in 2023. Yet 2024’s numbers far outpaced the 18,617 cases seen in 2019 and 15,609 cases in 2018.
The disease can lead to serious complications, including pneumonia, seizures, brain damage, and death. Infants and young children are particularly at risk. Around a third of infants under six months old who came down with whooping cough in 2024 required hospitalization.
“The crux of the disease is that it’s caused by this particular bacteria, Bordetella pertussis, which creates a toxin, and that toxin can be very damaging to our lungs,” says Amy Edwards, associate professor of pediatrics at Case Western Reserve University School of Medicine.
Vaccination is the best way to protect against infection and severe disease. The diphtheria, tetanus, and pertussis, or DTaP, vaccine is given in five doses in infancy and early childhood. Immunity from vaccination and natural infection eventually wanes, and a booster shot is recommended at age 11 or 12 and every 10 years after, including for adults. The CDC advises pregnant people to get a booster during each pregnancy.