In a first test of the Trump administration’s ability to respond to an infectious disease emergency, its top health official has shied away from one of the government’s most important tools, experts said on Sunday: loudly and directly encouraging parents to get their children vaccinated.
Robert F. Kennedy Jr., the health secretary, was widely criticized as minimizing the measles outbreak in West Texas at a cabinet meeting on Wednesday. In a social media post on Friday, he took a new tact, saying that the outbreak was a “top priority” for his department, Health and Human Services.
He noted various ways in which the department is aiding Texas, among them by funding the state’s immunization program and updating advice that doctors give children vitamin A. But on neither occasion did Mr. Kennedy himself advise Americans to make sure their children got the shots.
The Centers for Disease Control and Prevention, part of H.H.S., did not send its first substantive notice about the outbreak until Thursday, almost a month after the first cases in Texas were reported.
“They’ve been shouting with a whisper,” said Dr. Michael Osterholm, who is an epidemiologist at the University of Minnesota and a former health department official.
“I fear that their hands have been tied,” he added.
C.D.C. officials did not immediately respond to a request for comment.
The measles outbreak in West Texas has sickened more than 140 residents and killed one child, the first such death in a decade. The lukewarm endorsement of immunization and infrequent federal updates particularly concern scientists in light of Mr. Kennedy’s long track record of sowing distrust in vaccines.
Over the years, he has suggested that the vaccine for measles, mumps and rubella was associated with autism and that measles outbreaks were mostly “fabricated” to fatten drug makers’ profits.
If the Texas outbreak offers a window into the Trump administration’s approach to public health, it spells trouble for the future, some researchers said.
Health officials in the state say they have not needed extensive federal help, but future outbreaks in other places may not be manageable without federal assistance. “You could call this a dress rehearsal,” said Catherine Troisi, an epidemiologist at the UTHealth Houston School of Public Health.
She added: “In the theater, a bad dress rehearsal means a good performance. I actually am quite sure that’s not the case in public health.”
In past measles outbreaks, the C.D.C. often plays a leading role in educating the public about the dangers of contracting the virus and the importance of M.M.R. vaccinations.
At the height of an outbreak in New York in 2019, during President Trump’s first term, the agency issued a news release urging health care providers to reassure patients about the safety of the vaccine and criticizing groups that spread misleading information about it.
In an accompanying statement, Alex M. Azar II, the health secretary at the time, wrote that measles was a “highly contagious, potentially life-threatening disease.”
“With a safe and effective vaccine that protects against measles, the suffering we are seeing is avoidable,” he added.
His message was part of an intense campaign to quell the largest outbreaks since 2000, when measles had been declared eliminated from the United States. Vigorous campaigns led to more than 60,000 M.M.R. immunizations in the affected communities.
Health officials reached out to religious leaders, local doctors and advocacy groups. In parts of New York, officials declared an emergency, mandated immunizations and barred unvaccinated children from public places.
The signals this time around have been far more muted.
By the time the C.D.C. released its first public statement about the outbreak, measles had spread to nine counties in Texas, and nine additional cases had broken out in bordering New Mexico.
The statement mentioned vaccination once, saying it “remains the best defense against measles infection.”
When asked about the cases in Texas on Wednesday, Mr. Kennedy said the outbreak was “not unusual,” and falsely claimed that many people hospitalized were there “mainly for quarantine.”
He did not mention vaccines. In his post on social media, Mr. Kennedy emphasized that his department would “continue to fund Texas’ immunization program.” But he did not explicitly call for Americans to get the shots.
Instead, the vaccination campaign has largely been left to state and local officials. In Texas, there have been frequent news conferences, vigorously promoting vaccine clinics and debunking misinformation.
Senator Bill Cassidy, a Louisiana Republican who is a doctor, and who cast a crucial vote to confirm Mr. Kennedy to his post, urged residents of his state, which borders Texas, to make sure they were up-to-date on their measles vaccinations.
But a virus as contagious as measles does not respect state boundaries, and the C.D.C. should be providing greater national guidance and leadership, Dr. Osterholm said.
“Any location could be the next hot spot tomorrow,” he said.
On Friday, the Texas capital, Austin, reported a case of measles in an unvaccinated infant who had been exposed during international travel.
