The Verdict [False]
Long COVID was reported before COVID-19 vaccine authorization and roll-out.
What’s the claim?
Posts on social media falsely claim that a recent Yale study shows long COVID to be an injury caused by the COVID-19 vaccines. Long COVID is a serious long-term effect that can occur after a COVID-19 infection.
“They are finally admitting ‘Long COVID’ is just vaccine injury,” said a post on Facebook, sharing a screenshot of a headline that reads, “Yale Researchers Find COVID Spike Protein in Blood 709 Days After Vaccination, Positing Millions of Long COVID Patients May Actually Be Vaccine Injured.”
The headline seemingly originates from a Substack blog post published on February 19, 2025.
“Yale researchers released a study today that posits millions of Americans thought to have Long COVID may have been misdiagnosed and actually have post-vaccination syndrome caused by exposure to the spike protein in COVID vaccines,” the blog post reads.
However, long COVID was reported before vaccine rollouts, and the study does not claim that long COVID is a vaccine injury, just that there’s an overlap in symptoms.
What are the facts?
Cases of long COVID were reported in 2020, before vaccine authorization and roll-out.
The recent study, conducted by researchers from Yale School of Medicine and published on February 18, 2025, does not find that long COVID is actually a vaccine injury, and nowhere does the study make any such claim.
The study does note that “individuals have reported post-vaccination symptoms resembling long COVID beginning shortly after vaccination,” and that there is “considerable overlap” in self-reported symptoms between long COVID and post-vaccination syndrome.
Authors also note that vaccinated individuals experience a lower incidence of long COVID.
The study looked to explore potential pathobiological features associated with post-vaccination syndrome, a chronic debilitating condition reported by a small fraction of people after COVID-19 vaccination. It involved a small sample of 42 post-vaccination syndrome participants and 22 healthy controls.
The researchers measured for levels of coronavirus spike protein, used in COVID-19 vaccines to trigger immune responses, and found that some individuals with post-vaccine syndrome—even some that showed no evidence of having been infected with COVID-19—had higher levels of spike protein than controls. Some had detectable levels of spike protein more than 700 days after their last vaccination.
“We don’t know if the level of spike protein is causing the chronic symptoms, because there were other participants with PVS [post-vaccination syndrome] who didn’t have any measurable spike protein. But it could be one mechanism underlying this syndrome,” Akiko Iwasaki, a professor of immunobiology at Yale School of Medicine and co-author of the study, said in a press release.
The study is currently in preprint, meaning that it has not been certified and validated by peer review.
Logically Facts has reached out to the authors of the study for comment.
Iwasaki told Reuters that many people developed long COVID before vaccines were available and that a small study by her group found that “most people” with long COVID who had never been vaccinated improved their health after receiving COVID-19 vaccination.
Harlan Krumholz, another co-author of the study and a cardiologist at Yale School of Medicine, told Reuters that the claim that their research suggests long COVID symptoms are due to vaccine injury is entirely false and a misrepresentation.
The verdict
Cases of long COVID were reported before vaccine authorization and roll-out. Authors of the Yale study say that the claim that their research suggests long COVID symptoms are due to vaccine injury is false. Therefore, we have marked this claim as false.
This article is written by Nikolaj Kristensen and republished from Logically Facts. Read the original article here.
Reference Links
Post COVID-19 condition (long COVID) – WHO – Refutes
LONG COVID – Sky News – Refutes
Coronavirus: Thousands say debilitating symptoms last ‘for weeks’ – BBC – Refutes
Immunological and Antigenic Signatures Associated with Chronic Illnesses after COVID-19 Vaccination – medRxiv – Refutes
Immune markers of post-vaccination syndrome indicate future research directions – Yale News – Refutes
Fact Check: US study does not suggest long COVID is a vaccine injury – Reuters – Refutes
Also read | No, the number 19 in COVID-19 does not stand for ‘artificial intelligence’