Rates of pertussis, also known as whooping cough, are surging in Texas, Florida, California, Oregon, and other states and localities across the country.
The outbreaks are fueled by falling vaccination rates, fading immunity, and delays in public health tracking systems, according to interviews with state and federal health officials. Babies too young to be fully vaccinated are most at risk.
“Pertussis cases increase in a cyclical fashion driven by waning immunity, but the size of the outbreak and the potential for severe outcomes in children who cannot be vaccinated can be mitigated by high coverage and good communication to folks at risk,” said Demetre Daskalakis, a former head of the Centers for Disease Control and Prevention’s immunization program, who resigned in August.
Before the first pertussis vaccine became available in the early 1900s, whooping cough was one of the most common childhood diseases and a major cause of childhood death in the United States. Today, children get a series of DTaP shots (full-dose version) starting at 2 months old, and teens and adults receive a Tdap booster (lower-dose version) every 10 years. (Both vaccines target diphtheria and tetanus in addition to pertussis.)
Until recently, 8 in 10 toddlers had received four doses of the DTaP vaccine by age 2, and case rates were controlled. But vaccine coverage has declined since the covid pandemic and increases in state nonmedical exemptions have widened immunity gaps, which is when the proportion of individuals who are immune falls below the level needed to contain spread.
Texas logged 1,928 pertussis cases in 2024. By October 2025, the state had exceeded 3,500. National numbers are just as stark: In th …