PORTLAND, Ore. — Oregon has recorded its highest number of pertussis cases ever, prompting state health officials to urge residents—especially those who are pregnant or spend time around infants—to ensure they are up to date on vaccinations.
As of Dec. 10, the Oregon Health Authority (OHA) has confirmed 1,475 pertussis cases in 2025, surpassing the previous annual record of 1,420 set in 1950. The current outbreak began in spring 2024, when cases climbed to 1,252 by the end of the year. Several other states have reported similar increases.
Infants Most at Risk
Pertussis, or whooping cough, can cause severe illness at any age, but infants face the greatest risk of hospitalization and death. The American Academy of Pediatrics recommends that pregnant individuals receive a Tdap vaccine during the third trimester to provide newborns with protection until they can be vaccinated at two months old. Adults who will spend time around a newborn—such as partners, grandparents and caregivers—are also encouraged to get vaccinated at least two weeks before the baby’s birth.
Vaccination remains important across all age groups. Tdap is recommended for pregnant people, children beginning at 2 months old, adolescents at 11–12, and adults who have never received a dose.
“I worry people may not fully appreciate the risk pertussis poses as case counts are rising, especially for babies and older adults,” said Dr. Howard Chiou, medical director for communicable diseases and immunizations at OHA. He noted that maternal vaccination rates in Oregon have declined in recent years.
Declining Immunization Rates
According to OHA’s new Pregnancy Immunization Data dashboard, 69% of pregnant people in Oregon received a Tdap vaccine in 2024, down from 72% in 2020. Rates vary widely by county, ranging from 17% to 82%, with the lowest numbers largely in rural areas where access and vaccine hesitancy pose barriers.
So far in 2025, Oregon has reported 87 cases of pertussis in infants under 12 months, including 22 hospitalizations. One infant in the state has died from the illness this year.
A Post-Pandemic Surge
Pertussis outbreaks typically occur every three to five years, but case numbers dropped sharply during the COVID-19 pandemic, when masking and social distancing limited the spread of many respiratory infections. Oregon saw just three cases in 2021, followed by 17 in 2022 and 40 in 2023. Health officials attribute the resurgence to a return to pre-pandemic behaviors combined with waning immunity and reduced vaccination rates.
Why Vaccination Still Matters
Studies show that Tdap vaccination during pregnancy is highly effective at preventing severe illness and hospitalization in infants. But because immunity fades over time, some residents misunderstand the need for booster doses, said Dr. Carolina Amador, Benton County’s health officer.
“When we use the word ‘booster,’ people may think the vaccine isn’t very effective because protection fades,” Amador said. “But in the short term it does a great job protecting the most vulnerable among us.”
The Disease and Its Diagnosis
Pertussis spreads through respiratory droplets when an infected person coughs or sneezes. Many cases go undiagnosed because symptoms vary widely, and not everyone develops the characteristic “whooping” sound.
Dr. Jennifer Gibbons, a naturopathic pediatrician in Portland who works with vaccine-hesitant families, said she often counsels expectant parents about the importance of maternal vaccination.
“When parents ask me, ‘Do you think it’s right for me?’ the answer is always yes,” she said. Gibbons described whooping cough in infants as “truly awful,” and said explaining how maternal antibodies work can help parents better understand the benefits.
OHA has posted videos of Dr. Chiou discussing the outbreak on its Media Resources page.
Jordan Vawter
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