Moderna has halted its mRNA respiratory syncytial virus (RSV) vaccine trial for young children due to safety concerns. “A briefing document from the Food and Drug Administration (FDA) says that enrollment for all clinical studies of vaccines for respiratory syncytial virus (RSV) in infants is on hold over concerns about potential safety findings from a clinical trial involving two vaccine candidates,” the Center for Infectious Disease Research and Policy (CIDRAP) stated. According to the document, a phase I trial of two experimental Moderna RSV vaccines for infants aged five to eight months was paused in July. Reports stated five infants were hospitalized due to severe or very severe respiratory complications after receiving the experimental vaccine. “The observed imbalance in severe/very severe cases of RSV LRTI in the mRNA-1345 and mRNA-1365 vaccine development program among 5-month to <8-month-old recipients of mRNA-1345 (15 μg) and mRNA-1365 (15 μg) has uncertain implications for the ongoing and future pediatric development of other non-live attenuated RSV vaccines,” the FDA said, according to CIDRAP. MODERNA HALTS pediatric RSV trial after "at least five cases of severe or very severe RSV lower respiratory tract infections in infants immunized with Moderna’s investigational RNA vaccines." pic.twitter.com/EgVzeiqqtD — JaxenReport (@JaxenReport) December 11, 2024 Fortune reports: The document notes that a phase 1 trial of two experimental Moderna RSV vaccines in infants aged five to eight months was paused in July. The pause came after five cases of severe to very severe lower RSV respiratory tract infections were reported among the 40 babies who received the vaccine dose, compared with just one case in the placebo group of 20. Five infants required hospitalization, with one needing mechanical ventilation. It all “has uncertain implications for the ongoing and future pediatric development of other non-live attenuated [inactivated] RSV vaccines,” said the FDA, which put a hold on the trial after the July incident. You probably haven't read about this on the mainstream media… Moderna has been forced to pause trials of their new mRNA injection after five infants were hospitalized. Not safe and not effective.https://t.co/v24K95euhQ — PeterSweden (@PeterSweden7) December 17, 2024 According to Fierce Pharma, an FDA advisory panel expressed frustration about its inability to conclude the safety and effectiveness of the experimental shots. The simple conclusion should be that it is NOT SAFE AND NOT EFFECTIVE. Per Fierce Pharma: The halt was triggered by an “imbalance,” the FDA said, in cases of severe lower respiratory tract infections (LRTIs) in children in a phase 1 trial of two Moderna RSV vaccines. One of the shots, mRNA-1345, was approved by the FDA in May of this year and is dubbed mRESVIA. In that phase 1 trial—which was conducted in Panama and included infants as young as 5 months—five children developed severe LRTIs, with four going to the hospital. The trial had been opened up to younger children after there were no safety issues involving kids ages 8 to 23 months who had received one of the vaccines. There is some concern that the shots can cause or worsen the disease in the younger age group. No vote was taken during Thursday’s meeting to recommend regulatory action. The goal of the VRBPAC discussion was to inform future testing. After hearing presentations from Moderna on its trial findings and from the FDA, the advisory committee members generally agreed that RSV shots for infants should be examined on a “vaccine platform-by-vaccine platform basis,” according to Arnold Monto, M.D., an epidemiology professor at the University of Michigan. “The clinical trial for Moderna’s mRNA shot for RSV in children found ‘Severe illness was 26.3% in the vaccine groups compared with 8.3% in the placebo.’ Talk about “the more you inject, the more you infect!'” The Blaze Senior Editor Daniel Horowitz wrote. The clinical trial for Moderna's mRNA shot for RSV in children found “Severe illness was 26.3% in the vaccine groups compared with 8.3% in the placebo.” Talk about “the more you inject, the more you infect”! My latest @theblaze https://t.co/Z3OkzO1Af6 — Daniel Horowitz (@RMConservative) December 17, 2024 “The @US_FDA disclosed this week in a briefing document that rather than protecting babies as anticipated, the vaccine likely caused higher rates of severe RSV illness among the vaccinated babies enrolled in the Phase 1 clinical trials,” Children’s Health Defense noted. “FDA is trying to cover itself, to avoid claims of negligence. It should have anticipated VAERD, because it happened before in RSV trials — and killed babies — and because it is happening now with the COVID vaccines, which, after roughly 6 months, depending on age and dose, make the recipient more likely to get COVID,” Dr. Meryl Nass said, according to the outlet. Moderna Shuts Down mRNA RSV Vaccine Trial in Babies After Shots Linked to Severe Side Effects, FDA Document Reveals The @US_FDA disclosed this week in a briefing document that rather than protecting babies as anticipated, the vaccine likely caused higher rates of severe RSV… pic.twitter.com/2K82DStw7p — Children’s Health Defense (@ChildrensHD) December 12, 2024 From CIDRAP: Moderna was made aware of the safety signal and paused further enrollment on July 17 and notified the FDA of the study-wide pause on July 19, according to the document. The FDA then put a clinical hold on the trial. On September 12, Moderna announced that the RSV program for seronegative children—those without detectable RSV antibodies—younger than 2 years old was listed under discontinued programs. The trial also found that vaccine immune responses in infants who received mRNA-1345 and had previously been exposed to the monoclonal antibody nirsevimab were blunted compared with those who had not received nirsevimab, suggesting a possible interaction. Marketed under the brand name mRESVIA, mRNA-1345 was approved by the FDA in May for use in adults aged 60 and older. It’s one of three RSV vaccines that have been licensed for adults and pregnant women within the past 2 years. Moderna is conducting a phase 1 trial of mRNA-1365 as combination vaccine for RSV and human metapneumovirus. Read the FDA briefing document HERE.