The Studies Not Run

A vaccine trial measures harm by comparing the people who received the product with people who did not. What the comparison group receives determines what the trial can detect. Three kinds of control appear in the vaccine record, and public statements routinely treat them as one.

In the second and third designs, any harm common to both arms cancels out of the comparison. A trial that gives both groups aluminum cannot find a harm caused by aluminum.

The Institute recommended that the comparison be made using records the government already held, through the Vaccine Safety Datalink. It ruled out a randomized trial as unethical. The Datalink studies that followed examined single vaccines, single outcomes, or partly vaccinated children. None compared the full schedule with no vaccination across chronic disease.

The letter is the agency's own statement of what it has done. The Institute of Medicine had named the comparison in 2013 and pointed to the data CDC already held. The letter is about studies CDC itself conducted and does not address studies by others, such as the Henry Ford manuscript in section 3.5.

Inert-placebo trials do exist in the record. The 1954 Salk polio trial randomized more than 600,000 children to vaccine or saline, and later placebo-controlled trials exist for some newer products. According to ICAN's 2018 reply to HHS, few products on the current schedule were licensed that way.

The Institute of Medicine resolved this by pointing to observational data the government already held. An observational study of existing records requires no child to go unvaccinated, so the ethical objection does not apply to it. No Datalink study of that kind has been published.

The study was completed around 2020. It entered the public record only on 9 September 2025, when it was submitted to a Senate subcommittee. Siri testified that the authors regarded the study as well done and declined to submit it for publication for stated personal reasons. Henry Ford Health said its senior scientists had found fatal flaws, and that the vaccinated and unvaccinated groups differed. The study was not submitted for peer review, where those objections could have been tested, and the institution sent a cease-and-desist letter to filmmakers who covered it.

The principal objection is that unvaccinated children visit doctors less often and so receive fewer diagnoses. The authors tested this. Restricting the analysis to children who had at least one clinical visit reduced the hazard ratio for any chronic condition from 2.53 to 1.87, which remained elevated. The authors wrote that their findings could not prove causation and warranted further investigation. No follow-up study has been published.

The largest study cited against the signal, a 2025 Danish registry of 1.2 million children, compared children who received more aluminum with children who received less. It contained no group that received none. It could not detect a harm present at every level of exposure, which is the question the asthma signal raises.

The evidence on both sides is thin. The five-fold estimate rests on sixteen deaths. A 2025 reanalysis found that the same research group's own randomized trials mostly failed to show the effects they were designed to detect, and a 2026 audit listed ten of the group's registered trials with primary outcomes partly or wholly unpublished, one of them a DTP-related trial reported to have enrolled 6,534 children. No one has run the randomized trial the WHO review called for, so the question remains open.

The Act's liability protection has applied since 1988. In 2018 HHS had no record of any report under the same Act's reporting requirement, and the public learned of the gap through a private group's lawsuit.

The same year, the FDA approved Moderna's mRNA influenza vaccine on the strength of a 26.6 percent efficacy advantage over an existing flu vaccine. The trial had no unvaccinated arm, so its efficacy figure is relative to the licensed comparator.

Each gap described above was identified by a responsible body or by the researchers themselves. In 2013 the Institute of Medicine named the missing schedule comparison and the data system that could make it. The Henry Ford authors and the CDC-funded asthma authors called for further study, the WHO review called for trials, and Congress required periodic reports.

The bodies that hold the authority and the data have not produced these studies or reports. The schedule's safety record therefore contains no comparison capable of detecting a harm shared across vaccines or one that appears years after vaccination.