A report released by Sen. Ron Johnson, chairman of the Senate Permanent Subcommittee on Investigations, alleges that officials at the Food and Drug Administration knew as early as March 2021 that the government’s primary vaccine safety surveillance system contained a critical flaw — and that rather than correcting it, they shut down the researcher who found the problem. The report, titled “Unmasked: How Biden Health Officials Purposely Turned a Blind Eye Toward COVID-19 Vaccine Safety Signals,” draws on 11 million pages of internal documents obtained through the subcommittee’s oversight work, including records compelled through a January 2025 subpoena to the Department of Health and Human Services.
The Flaw in the System: What Is “Masking”?
At the center of the report is Dr. Ana Szarfman, a senior medical officer and safety data-mining expert at the FDA. According to the subcommittee’s findings, in March 2021 Szarfman alerted FDA leadership to a statistical problem embedded in the Vaccine Adverse Event Reporting System, commonly known as VAERS — the primary passive surveillance tool used by both the FDA and CDC to track potential vaccine side effects.
The problem is called “masking.” It occurs when a high volume of reports associated with one product artificially inflates the statistical baseline used to evaluate the entire database, making it harder for genuine safety signals from any individual product to register as statistically significant. According to testimony presented at the subcommittee’s hearing by Dr. David Wiseman, “Masking occurs when statistical signals for one vaccine in a database are obscured by reports associated with other vaccines. For example, Moderna’s myocarditis signal becomes hidden if its comparison baseline is artificially inflated by including Pfizer’s myocarditis reports.”
During the COVID-19 vaccine rollout, the unprecedented volume of reports flooding into VAERS created conditions that the report alleges were ideal for this kind of distortion.
The Improved Method That Uncovered Hidden Signals
Szarfman did not simply identify the problem — she proposed a solution. She recommended switching to a more sophisticated analytical method called the Regression-Adjusted Gamma Poisson Shrinker, or RGPS, which she described as a “state of the art” algorithm specifically designed to correct for masking effects.
When applied to the VAERS data, the results were significant. Szarfman’s analysis using the RGPS method uncovered 49 examples of “extreme masking” within the database and identified approximately 25 previously undetected safety signals. Among those signals were sudden cardiac death, pulmonary infarction, and Bell’s palsy — conditions that had not been flagged by the standard algorithm then in use.
According to the subcommittee’s report, this work was not embraced by FDA leadership. Instead, it was stopped.
The “Cease and Desist” Order
Internal communications obtained by the subcommittee show that Dr. Peter Marks, director of the FDA’s Center for Biologics Evaluation and Research (CBER), warned that Szarfman’s data-mining work could “create erroneous conflicts that feed into anti-vaccination rhetoric.” The report alleges that within months of her initial findings, Szarfman was formally instructed to “cease and desist” her work using the RGPS method.
The suppression of her analysis was not the only restriction documented in the report. The FDA also began curtailing the weekly VAERS data-mining reports it had been sharing with the CDC, gradually cutting off access to that internal reporting stream. The subcommittee’s findings suggest these decisions were made in a context where protecting the vaccine rollout and securing full licensure for the COVID-19 vaccines were institutional priorities.
A Parallel Track: The Myocarditis Warning That Was Delayed
The masking issue was not the only area where the subcommittee found evidence of delayed or suppressed safety information. A separate interim report released by the Permanent Subcommittee on Investigations in May 2025, titled “Failure to Warn: How Federal Health Agencies Downplayed the Risk of Myocarditis and Other Adverse Events Following COVID-19 Vaccination,” examined how CDC and FDA handled the emerging myocarditis signal in early 2021.
That report drew on unredacted records obtained through the subpoena process, after years of what the subcommittee characterized as obstruction by the Biden administration. According to the interim report, many of Chairman Johnson’s more than 70 oversight letters to Biden-era HHS officials were either completely ignored or inadequately addressed. Records that the subcommittee states should have been provided to Congress and the public years earlier were only produced after the change in administration and HHS leadership.
The interim report also noted that in April 2021, a Defense Health Agency consultant warned HHS officials that V-safe — another vaccine safety monitoring system — may not be capable of detecting cardiac adverse events due to limitations in its survey design. An updated V-safe protocol issued in May 2021 reportedly failed to address those concerns.
Additionally, unredacted communications from March 2021 show that the CDC expressed “particular interest in hearing about deaths reported after vaccination,” a detail that had previously been obscured in FOIA-produced versions of those documents.
What the VAERS Data Currently Shows
VAERS, the passive reporting system at the center of the subcommittee’s findings, now contains over 1.6 million adverse event reports associated with COVID-19 injections, including 39,099 reported deaths. Of those deaths, 9,332 are recorded as having occurred within two days of injection. It is a standard caveat of VAERS — stated explicitly on the FDA’s own website — that a report to the system does not establish that a vaccine caused the event, and that some reports may represent coincidental occurrences unrelated to vaccination. However, VAERS was specifically designed as an early-warning system, and the subcommittee’s report argues that the masking flaw undermined its ability to perform that function during the critical early months of the COVID-19 vaccine rollout.
Media Outlets Decline to Publish Johnson’s Op-Ed
In describing the public reception of the report’s findings, Sen. Johnson noted that major media outlets — including the Wall Street Journal, the New York Times, and Fox Digital — declined to publish his op-ed summarizing the findings. Johnson has described the events documented in the report as the biggest government scandal of his lifetime.
Whether that characterization holds up to broader scrutiny remains a matter of ongoing debate. What the subcommittee’s documents do establish — through internal communications, subpoenaed records, and testimony — is a timeline in which federal health officials were alerted to potential problems with safety surveillance systems in the early months of the vaccine rollout, and in which at least one researcher’s proposed improvements were discontinued rather than implemented.
The Broader Question of Institutional Accountability
The subcommittee’s work raises questions that extend beyond any single agency or official. The FDA’s own COVID-19 vaccine safety surveillance page describes its monitoring approach as “a coordinated and overlapping” system using “state of the art technologies” to maximize the ability to detect safety concerns. The report from Johnson’s subcommittee directly challenges whether that description accurately reflected what was happening inside the agency in 2021.
For the millions of Americans who received COVID-19 vaccines during that period — under a public health framework that relied on the integrity of these surveillance systems — the gap between what was known internally and what was communicated publicly is not an abstract bureaucratic concern. The full scope of what federal health officials knew, when they knew it, and what decisions were made as a result remains a subject that the subcommittee says it intends to continue investigating as additional documents are produced.
This article draws on reporting from Activist Post and documents published by the U.S. Senate Permanent Subcommittee on Investigations, as well as the FDA’s COVID-19 Vaccine Safety Surveillance page.
