Federal health investigators say the Biden-era FDA and CDC identified a notable stroke risk tied to Pfizer’s COVID-19 bivalent booster in seniors—and still did not warn the public.
Misryoum newsroom reported that Senate investigators spent months reviewing roughly 2,000 pages of federal records. In a formal letter to HHS Secretary Robert F. Kennedy Jr., Sen. Ron Johnson (R-WI), chairman of the Senate’s Permanent Subcommittee on Investigations, laid out what he says is in the files. Johnson wrote that HHS records show federal health officials identified a potential connection between the Pfizer-BioNTech COVID-19 bivalent booster and ischemic stroke for individuals over the age of 65 as early as October 2022. An ischemic stroke means a blockage of blood to the brain.
Between November 2022 and March 2023, Johnson said, seven separate analyses of incoming data flagged the same stroke signal—specifically in adults over 65. Misryoum newsroom reported that CDC data cited by Johnson shows 226 stroke cases reported between August 2022 and February 2023, with additional cases surfacing throughout 2023 and 2024. And still, Johnson says the Biden administration issued no formal warnings—no Health Alert Network message, no changes to booster recommendations for seniors.
Instead of public guidance, Johnson said the administration quietly hired a private contractor, Lukos LLC, to conduct a deeper internal investigation dubbed “The Stroke Project” in February 2023. Publicly, officials kept insisting the vaccines were safe. “From the initial detection of the safety signal in late 2022 … health officials continued to say the vaccine was safe while simultaneously searching for evidence to support that assertion,” Johnson said. The phrasing lands weirdly—like they were trying to reassure people, while also looking for proof, or maybe looking for the part that would make the reassurance easier to defend.
There’s also the matter of how officials planned to talk about the risk. Misryoum editorial team stated that federal officials drafted a communications plan about the stroke risk that included a “Tough Questions and Answers” section prepared for President-ish Biden and his White House team. During final edits, Johnson said, the description of the stroke signal was quietly changed from “moderately elevated” to “slightly elevated.” Who made that change? Nobody knows. The language softened, the edit went unattributed, and the public remained in the dark.
Misryoum analysis indicates the pattern matches earlier complaints from Senate investigators about vaccine messaging—specifically that Biden officials downplayed myocarditis risk and kept it from the public. It’s being framed as a system, not a one-off stumble. And the argument gets sharper when you look at what the administration did in another vaccine context.
Misryoum newsroom reported that in April 2021, officials paused the Johnson & Johnson (Janssen) vaccine due to blood clot concerns. At the time of the pause, Misryoum editorial desk noted that six cases of severe blood clots had been reported out of nearly 7 million doses administered. Johnson’s letter argues that when 226 stroke cases surfaced tied to Pfizer’s bivalent booster in the most vulnerable seniors, the administration did nothing. The claim is that this double standard wasn’t accidental—it was deliberate.
Even so, the fallout is what keeps coming up: public trust. According to the Kaiser Family Foundation, fewer than half of all Americans now trust the CDC and FDA to operate free from political or special-interest influence. And in the quiet hours when you scroll through these kinds of records, it’s hard not to feel that the “quiet” part is the real headline—like a door that never fully opens, just clicks shut, again and again.