Shares of Pfizer and Moderna fell on Friday after a report that Trump administration health officials plan to link Covid vaccines to the deaths of 25 children. 

The report from the Washington Post said officials plan to include the claim in a presentation next week to a key vaccine panel that advises the Centers for Disease Control and Prevention.That committee plays a critical role in determining vaccine access, as it reviews immunization data and makes recommendations on who is eligible for shots and whether insurers should cover them, among other duties.

But the presentation to that panel is not final, the Post reported.

“FDA and CDC staff routinely analyze VAERS and other safety monitoring data, and those reviews are being shared publicly through the established ACIP process,” a spokesperson for the Department of Health and Human Services said in a statement, referring to the panel, the Advisory Committee on Immunization Practices.

“Until that is shared publicly, any this should be considered pure speculation,” the spokesperson added.

Pfizer’s stock fell more than 3% on Friday, while shares of Moderna dropped more than 7%. Novavax, which creates protein-based Covid shots, slid more than 4%.

The report comes as Health and Human Services Secretary Robert F. Kennedy Jr. moves to change vaccine policy in the U.S. He has dropped Covid shot recommendations for healthy kids and pregnant women and set new limits on the approval of new jabs against the virus.

In a statement, Moderna said the safety of its vaccine is “rigorously monitored” by the company, the FDA and regulators in more than 90 countries. Systems across the U.S., Australia, Canada and Europe have not identified “any new or undisclosed safety concerns in children or in pregnant women,” Moderna added.

Pfizer did not immediately respond to a request for comment.

Numerous studies have demonstrated that shots using mRNA technology, including Covid vaccines from Pfizer and Moderna, are safe and effective, and serious side effects have happened in extremely rare cases.

Researchers have noted an elevated but rare risk of myocarditis, or inflamed heart muscle, in young men in particular. But there is no evidence that the vaccines in use now cause any other major safety risks, including pediatric deaths. Global surveillance data also continue to generally show that the benefits of Covid vaccination outweigh the risks in pediatric populations.

The Washington Post said the claim appears to be based on information submitted to the federal Vaccine Adverse Event Reporting System, which monitors the safety of shots approved or authorized by the Food and Drug Administration. The system contains unverified reports of side effects, including from patients, doctors and pharmacists.

Only scientists and public health officials can determine, after thorough investigation, whether a vaccine caused or contributed to a side effect submitted to the system, according to the CDC website.

Last week, FDA Commissioner Marty Makary told CNN the agency is conducting an “intense investigation” into whether Covid shots have caused deaths in children. He did not share specific data linking pediatric deaths to the vaccine, but pointed to self-reported incidents in the safety system database. 

The FDA plans to release a report in the coming weeks, Makary added.

“We do know at the FDA, because we’ve been looking into the [vaccine safety] database of self reports, that there have been children who have died from the Covid vaccine,” Makary told CNN.

During a Senate hearing last week, Kennedy said he supports a statement made by a newly appointed member of a key government vaccine panel that mRNA vaccines pose a dangerous risk to people.