Workers at two of the trial sites said the trial for the Epstein-Barr virus vaccine, which launched in early 2022, was paused. One of the workers said the trial was halted due to an issue with one of the participants.

“We received an update about an adverse event that initiated the pause for dosing, but I, myself did not receive details on what the event was,” Maurice Beck, recruitment manager for Tekton Research, told The Epoch Times via email.

The confirmation comes after independent reporter Alex Berenson reported on an email he obtained that announced the halt.

The message, titled “all dosing must pause immediately!” informed people that the adverse event was suspected to be myocarditis, a form of heart inflammation.

“We have been informed today of an adolescent subject … that has met a pause rule of ‘possible case of myocarditis,'” the email stated. “In line with protocol guidance, this necessitates an immediate suspension of all dosing for ALL adolescent subjects.”

A Moderna investigator was said to have sent the email on Nov. 16. The Lynn Health Science Institute also confirmed to The Epoch Times that the trial was paused.

Mr. Beck said on Nov. 17 that there was no projected timeline for resuming the trial but added on Nov. 21 that the dosing pause “was lifted within a week.”

UMass Chan Medical School, a third site, declined to comment, referring The Epoch Times to Moderna. The school, at the University of Massachusetts, was among the sites announcing the trial start in a press release.

“The goal is to raise robust immune responses to a broader range of proteins used by the virus for cell entry, in order to protect against infection and mononucleosis disease,” Dr. Katherine Luzuriaga, the principal investigator of the trial at UMass Chan, said at the time.

Multiple requests for comment to Moderna returned a one-away message from a spokeswoman while two other spokespeople did not respond.

The U.S. Food and Drug Administration, which regulates vaccines, declined to provide a comment by press deadline. Moderna has not publicly disclosed the halt of the phase 1 trial, which is known as Eclipse.

Companies are required to disclose to the U.S. Securities and Exchange Commission “on a rapid and current basis” information “concerning material changes in the financial condition or operations” under the Sarbanes-Oxley Act and subsequent commission rules.

The disclosures are made through form 8-K. Moderna has filed two form 8-Ks in November but did not mention the trial in either.

Dr. Andrew Bostom, a retired professor of medicine who has run clinical trials, said that Moderna is required to let study coordinators and participants know about the development.

Moderna’s COVID-19 vaccine causes myocarditis, though there’s no consensus on the mechanism by which the inflammation is caused.

Dr. Bostom told The Epoch Times in an email that the apparent case of myocarditis following Epstein-Barr vaccination raises concerns about the messenger RNA platform that Moderna uses for both the Epstein-Barr and COVID-19 vaccines.

The case “suggests the platform itself is causing inflammation, such as myocarditis, and the platform itself needs to be re-evaluated,” Dr. Bostom said. “A moratorium should be put in place until the mechanism of this potentially fatal inflammatory is better understood and eliminated.”

Epstein-Barr Vaccine Trial

Moderna announced in January 2022 that the first participant in the trial for the experimental Epstein-Barr vaccine had been dosed.

“The start of this Phase 1 study is a significant milestone as we continue to advance mRNA vaccines against latent viruses, which remain in the body for life after infection and can lead to chronic medical conditions. Moderna is committed to developing a portfolio of first-in-class vaccines against latent viruses for which there are no approved vaccines today,” Stephane Bancel, Moderna’s CEO, said at the time.

Moderna currently has no cleared products besides its COVID-19 vaccine.

The Epstein-Barr virus, named after scientists Anthony Epstein and Yvonne Barr, who discovered it, is a herpesvirus that typically spreads through saliva and other bodily fluids. It can cause illnesses such as infectious mononucleosis, which is commonly known as mono.

The virus infects many people, including about 95 percent of adults, according to the Cleveland Clinic. A number of people contract the virus during childhood. Latent viruses remain in the body after infection and can later contribute to other conditions.

The randomized, controlled trial was launched in about 15 sites in the United States. The first part was aimed at examining the safety and tolerability of the vaccine in adults aged 18 to 30 and enrolled about 270 adults.

Part B of the trial enrolled adolescents aged 12 to 17. Participants had to be in good general health, according to Moderna’s website. Participants with a history of myocarditis and/or pericarditis, a related condition, were barred from enrolling.

About 150 adolescents have been enrolled, according to the website. Participants were said to spend 18 months in the trial, with up to 15 site visits and 10 safety calls.