When there’s an outbreak of a vaccine-preventable disease, state health officials typically take certain steps to alert residents and issue public updates about the growing threat.

That’s standard practice, public health and infectious disease experts told NPR and KFF Health News. The goal is to keep as many other vulnerable people as possible from getting sick and to remind the public about the benefits of vaccinations.

But in Louisiana this year, public health officials appeared not to have followed that playbook during the state’s worst whooping cough outbreak in 35 years.

Infants are not eligible for their first pertussis vaccine until they’re 2 months old, but they can acquire immunity if their mother was immunized while pregnant.

By late January 2025, two babies had died in Louisiana.

But the Louisiana Department of Health waited two months to send out a social media post suggesting people talk to their doctors about getting vaccinated.

In late January 2025, physicians inside one Louisiana hospital warned their colleagues that two infants had died in the outbreak.

On Feb. 13, the state’s surgeon general, Ralph Abraham, sent a memo to staff ending the general promotion of vaccines and community vaccine events.

He sent that email a few hours after Robert F. Kennedy Jr., an anti-vaccine activist, won Senate confirmation as the new U.S. health and human services secretary.

Also that day, Abraham posted a public memo on the Louisiana Department of Health’s website. In it, he said public health had overstepped with vaccine recommendations, which, he said, are driven by “a one-size-fits-all, collectivist mentality.” Abraham has called COVID-19 vaccines “dangerous” and has been a vocal supporter of Kennedy.

Four days later, in response to a request from a TV news station in New Orleans, the Louisiana Department of Health confirmed the deaths of two infants from whooping cough for the first time, in an email. WVUE Fox 8 then published the news.

But the Louisiana Department of Health sent out no alerts, according to a review of external and internal communications by NPR and KFF Health News.

Over the next month, two more infants were hospitalized for whooping cough, according to internal health department emails, obtained through a public records request.

In March, after inquiries from NPR and KFF Health News about the growing number of pertussis cases, the health department put out its first social media communications about the outbreak and offered interviews to other journalists.

Then in May — at least three months after the second infant death — the health department issued what appears to be its first and so far only official alert to physicians. It put out its first press release, and it then held a press conference about pertussis on May 14.

By then, 42 people, three-quarters of whom were not up to date on their whooping cough immunizations, had been hospitalized for whooping cough since the outbreak began, according to the Louisiana Department of Health.

More than two-thirds of those hospitalized were babies under age 1.

Throughout the summer, cases of pertussis continued to climb in Louisiana. But there were no further public communications from the Louisiana Department of Health.

NPR and KFF contacted the department for comment on Sept. 25. A spokeswoman did not answer specific questions about the lack of communications but referred to a Sept. 30 post on X by the state surgeon general.

In the post, Abraham said the department “consistently reported cases of pertussis and provided guidance to help residents stay protected” in 2025. He called the pertussis vaccine “one of the least controversial” and said he recommends it to his patients.

Louisiana should have started warning the public within days or a week of the first infant’s death, instead of waiting months, said Stanford’s Karan.

“At minimum, it should be like heavy promotion of, ‘Hey, infants are at high risk. They get infected by people who have waning immunity. If you haven’t gotten vaccinated, get vaccinated. If you have these symptoms, get tested,’” Karan said.

While deaths from a vaccine-preventable illness are tragic, they can also serve as an opportunity to educate the public about the benefits of vaccines and try to save lives, according to Dr. Joshua Sharfstein, a former health secretary for Maryland, and a professor at the Johns Hopkins Bloomberg School of Public Health.

"The risk of pertussis is always there, but when you have two infant deaths it’s a really good opportunity to communicate that this is a real threat to the health of children," Sharfstein said.

By not acting more quickly, Karan said he believes the department may have set itself up for a worse outbreak.

“Because then what we see is this train wreck thereafter, of like an insanely large outbreak, a lot of hospitalizations,” Karan said.