The pertussis vaccine works really well, according to a new study comparing kids in Alaska who had gotten three or more doses of the vaccine with children who were unvaccinated, or undervaccinated.

The diphtheria, tetanus, and acellular pertussis (DTaP) vaccine is a routine childhood combination immunization that's given in a five-dose series, starting at two months of age, with the last dose between the ages of four and six years.

A paper yesterday in the Morbidity and Mortality Weekly Report (MMWR) found that, compared with fully vaccinated children, those who were unvaccinated had approximately 26 times the odds of having a confirmed case of pertussis, sometimes called whooping cough, which is caused by a bacterial infection. 

The paper focused on kids from the ages of six months through six years during Alaska's 2024 pertussis outbreak, which saw the highest case rate on record in the state. Researchers from the Centers for Disease Control and Prevention (CDC) and Alaska Department of Health used records from VacTrAK, the database that tracks all vaccinations administered in the state. As a control, the study included kids who were treated for an acute cough, but either tested negative for pertussis or did not receive testing.

The overall adjusted vaccine effectiveness (VE) rate against pertussis among children who had received three or more DTaP doses was 96.2%. Also, VE was 85.3% among kids who were partially vaccinated, meaning they had received just one or two DTaP shots. 

These real-world findings support childhood vaccination recommendations, said the authors, who pointed to previous research showing that unvaccinated kids are more likely than those who are vaccinated to experience severe illness or require hospitalization.

Pertussis can lead to devastating outcomes among young children, including brain damage and deaths: A provisional CDC report found that 16 people died from this bacterial infection in 2025, including 10 infants. Other complications include pneumonia, vomiting after a coughing fit, or coughing that is so frequent and violent that a child fractures their rib. 

The DTaP vaccination rate among kindergartners in the United States has fallen in recent years. CDC data show it dropped to 92.0% for the 2025-26 school year; in 2017-18, it was 95.2%.

In August 2025, President Donald Trump deployed members of the National Guard and Immigration and Customs Enforcement (ICE) to patrol Washington, DC. The increase in visibility of federal troops and law enforcement had a chilling effect on Spanish speakers and Hispanic people’s willingness to seek healthcare, a paper published in JAMA Network Open this week finds. 

“The federal deployment of the National Guard troops, ICE, and other federal law enforcement personnel in Washington, DC, was associated with an immediate decline in pediatric ED [emergency department] visits,” wrote the authors, from Children’s National Hospital. “This decline was most pronounced among patients who preferred Spanish and among Hispanic patients regardless of preferred language.” 

Researchers wondered how the federal deployment in Washington, DC, affected the number of children visiting the hospital for emergency treatment. They compared daily pediatric ED visits from June 1 to September 30, 2025, with the same period in 2024 to see if federal law-enforcement activity affected who sought care. This included 21,822 visits from 6,253 (28.7%) Hispanic patients. 

People who spoke Spanish immediately changed how they interacted with healthcare after federal deployment and were less likely to go to the ED, averaging 10.4 fewer visits per day. But families who spoke English increased their number of ED trips by 5.6 more per day. 

These findings suggest that immigration enforcement may have unintended consequences for children’s use of emergency care.

Hispanic patients also shied away from pediatric EDs, with 13.3 visits fewer per day than in the previous year. In contrast, non-Hispanic patient visits rose by 6.2 per day. 

“These findings suggest that immigration enforcement may have unintended consequences for children’s use of emergency care,” the authors said.