Covid-19 vaccines were extremely protective, preventing millions of deaths. However, in a small number of people, vaccines may have led to a constellation of side effects that includes fatigue, exercise intolerance, cerebus, tinnitus and dizziness, collectively referred to as “post-vacination syndrome”, according to one New small study.
Some people with this syndrome seem to present distinct biological changes, discovered research-among them differences in immunological cells, reactivation of a sleeping virus called Epstein-Barr, and the persistence of a coronavirus protein in their blood.
The study was published online on Wednesday and has not yet been published in a scientific journal. “I want to emphasize that this is still a work ongoing,” said Akiko Iwasaki, a Yale University immunologist who led the work.
“It’s not like this study has determined what people are making,” she said, “but it’s the first glimpse of what may be happening to these people.”
Independent experts observed that the results were not conclusive by themselves. However, the results, from a scientific team known for their harsh work, suggest that post-vacination syndrome deserves further investigation, they said.
“One of the most important things is that we need attention to really illuminate this and try to understand exactly what it is,” said John Wherry, director of the University of Pennsylvania Institute of Immunology. (Wherry has previously collaborated with the Iwasaki team, but did not participate in this work.)
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Thousands of people stated that Covid vaccines damaged them. But the fragmented health system of the United States complicates the detection of unusual side effects and provided little clarity about the range of symptoms that people may have experienced after vaccination.
Fragmentation also made it difficult to compare and collect self-remedied accounts. The new study is small, and the condition it is studying is “very heterogeneous,” said Dr. Gregory Poland, Emeritus editor of Vaccine magazine and president of Atria Research Institute.
“Despite these limitations, they found interesting data that need more studies,” said Poland. “Much larger studies of carefully defined and phenotyped individuals need to be performed.”
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Between December 2022 and November 2023, Iwasaki and his team collected blood samples from 42 people with post-vaciness syndrome and 22 healthy people without the condition. People with the syndrome were usually in worse health than the average of Americans, the researchers discovered.
When the researchers analyzed components of the immune system, the subjects with post-vacination syndrome presented different proportions of some immunological cells compared to controls. It is unclear what these differences can mean; Researchers did not linked them to individual symptoms.
As symptoms reported by people with post-vacination syndrome show considerable overlap with those of Long Covid, researchers also analyzed the blood of 134 people with long covid and 134 healthy controls.
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Like people with long covid, those with post-vacination syndrome showed reactivation of the Epstein-Barr virus, a virus that can remain dormant in the body and is associated with mononucleosis, multiple sclerosis and other conditions.
Some cases of long covid are considered a result of coronavirus spike protein persistence, resulting in a high state of inflammation in the body.
Iwasaki and his team found that people with post-vacination syndrome had significantly higher plasma levels of coronavirus spike protein than everyone else-including those with long Covid-26 to 709 days after receiving the vaccine.
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Iwasaki said MRNA vaccines were probably not the source of protein so long after vaccine administration. “Something more is allowing this kind of late expression of Spike protein, and we don’t know exactly what it is,” she said.
Wherry suggested caution in the interpretation of this result. For example, it is possible that part of the protein results from uncontected coronavirus infections. “I would like to see more data about this topic,” he said.
Still, he added that the lack of clear answers makes it even more important to continue to explore the issue.
“One of the things that scientists perhaps have been taken a little during the pandemic is this perception that we should have all the answers, and if we can’t give a definite answer, then we shouldn’t talk about it,” he said.
“I think this is a mistake,” he added. “We cannot say for sure that this cannot happen.”
c.2025 The New York Times Company
