General Discussion

Health Secretary Robert F. Kennedy Jr. has said little publicly about vaccines in recent months, at the behest of a White House worried that his unpopular stance will hurt Republicans in November’s midterm elections. But he has not abandoned his quest for evidence that they are unsafe.

Working behind the scenes, Mr. Kennedy is spearheading an intense push, across health agencies under his purview, for government scientists and federal data contractors to examine his long-held theory that vaccines are helping to fuel an epidemic of chronic disease, according to multiple people familiar with the effort.

They said the wide-ranging inquiry is a top priority for Mr. Kennedy, who sees vaccines as a “potential culprit” in various neurological and autoimmune disorders, including asthma and allergies. It resurrects research into a number of ideas Mr. Kennedy has espoused, including whether vaccines are linked to autism and whether thimerosal, a preservative that has largely been removed from vaccines in the United States but remains in some flu shots, is dangerous....

The work is raising alarms among some vaccine scholars and critics of Mr. Kennedy, who have long accused the secretary of cherry-picking data and misinterpreting studies to claim that vaccines are unsafe and to limit their use. They fear Mr. Kennedy will use the findings to further erode confidence in vaccines, which the World Health Organization estimates saved 154 million lives over the past half-century.

Mr. Kennedy, who came into office saying he would do nothing to discourage people from getting vaccinated, has already taken steps to scale back the number of vaccines children receive. Public health experts complain that by spending money on issues that have already been thoroughly studied, he is taking funds away from research that might answer the very questions he is asking, including what causes autism.....

As part of the new effort, Mr. Kennedy has tasked some government scientists with studying the health status of vaccinated children compared with those who were not vaccinated. Mr. Kennedy coauthored a book, “Vax-Unvax: Let the Science Speak,” calling for such studies, which he believes will prove harm from vaccines.

Researchers say that such comparison studies would be riddled with pitfalls. Vaccinated children are more likely to receive medical care than those who are unvaccinated, and are thus more likely to receive additional medical diagnoses that could be wrongly attributed to vaccines.