The National Institute of Allergy and Infectious Diseases (NIAID) this week announced Bavarian Nordic’s mpox (monkeypox) vaccine is “safe and generates a robust antibody response in adolescents.”
The announcement drew criticism from doctors and scientists who cited the lack of any evident control group in the clinical trials and any publicly available data.
The results of the NIAID study, funded by the National Institutes of Health, could open the door for the vaccine’s approval for 12- to 17-year-olds in the U.S., a month after European regulators approved the vaccine for the same age group.
According to the Oct. 16 announcement, the modified vaccinia Ankara-Bavarian Nordic (MVA-BN), marketed as Jynneos in the U.S., “generated antibody levels in adolescents equivalent to those observed in adults at day 43 and found that the vaccine was well tolerated through study day 210.”
The results are based on a pair of Phase 2 clinical trials of the MVA-BN vaccine. One trial included 229 participants between 18 and 50 years old, while the other trial tested the vaccine on 315 adolescents between ages 12 and 17.
Based on the findings, the European Medicines Agency (EMA) last month approved the MVA-BN, marketed as Imvanex in Europe and the United Kingdom, for 12- to 17-year-olds.
“The immune response in adolescents was similar to adults. … According to the submitted data, the safety profile of Imvanex in adolescents was comparable to that seen in adults and no additional risk has been identified,” the EMA stated in its Sept. 19 announcement.
Last month, the World Health Organization (WHO) approved MVA-BN for adults — and said it can be used for babies, children, teens and pregnant women if they are in “outbreak settings where the benefits of vaccination outweigh the potential risks.”
The U.S. Food and Drug Administration (FDA) in September 2019 approved the Jynneos vaccine for adults, for the prevention of both mpox and smallpox and added it to the Strategic National Stockpile.
The approvals went through even though no data on the MVA-BN clinical trial results for the 12-17 age group have been publicized.
‘The complete void of any transparency in this clinical trial is stunning’
Critics of the vaccine cited the lack of data for 12- to 17-year-olds, the lack of a control group in the clinical trials, and questioned the necessity and safety of administering the mpox vaccine to children.
“The complete void of any transparency in this clinical trial is stunning,” said Brian Hooker, Ph.D., chief scientific officer for Children’s Health Defense. He added:
“Also, the clinical trial had no unvaccinated control group for comparison, which is a fatal flaw even if they would have made the trial results public. These are supposedly the premiere clinical researchers worldwide, yet they make 9th-grade mistakes in running their experiments.”
A spokesperson for NIAID who spoke with The Defender directed the public to the study protocol for the two clinical trials. However, the protocol does not indicate a control group and contains no findings.
“Short-term antibody responses in a study with an undisclosed sample size and no reported safety data are not sufficient for an NIAID press release,” cardiologist Dr. Peter McCullough told The Defender.
McCullough said:
“The Jynneos monkeypox vaccine has been used for years and carries a risk of myocarditis or heart damage. This study is not reassuring on safety or theoretical efficacy. The NIAID should take this post down and wait for the full peer-reviewed manuscript to be published.”
Internist Dr. Meryl Nass questioned the need for the MVA-BN clinical trials and NIAID’s claims of insufficient data for people 18 and younger. She told The Defender the studies were performed “after the U.S. government already gave hundreds of thousands of Americans both doses in mid-2022 and collected data on them.”
“One wonders what the purpose of this tiny trial was,” Nass said.
Data indicate a potentially high risk of severe adverse events
According to the NIAID announcement, “The overall frequency of adverse events was comparable between the study groups. Reports of dizziness were more common in adolescents than adults, but similar to the frequency of dizziness reported when other vaccines are administered in adolescents.”
The study results for the 18- to 50-year-old group indicated a rate of severe adverse events exceeding 1%. For Nass, a “1% SAE [severe adverse event] rate for a vaccine is very high,” though she added, “We need to know more to make any safety judgment.”
Nass suggested the actual number of severe adverse events may have been underreported.
“NIAID claims that only two of the 229 subjects had a serious adverse event. However, their definition of serious has been made more and more restrictive over the years,” Nass said.
According to Nass, while NIAID’s definition of a serious adverse event once “included an ER [emergency room] visit after vaccination,” the current NIAID definition is narrower, referring, in part, to “inpatient hospitalization or prolongation of existing hospitalization” instead of an ER visit.
The two reported severe adverse events in the 18-50 age group involved cases of cystitis — an inflammation of the bladder — and euglycemic diabetic ketoacidosis, an “uncommon diabetic complication.”
Nass also noted that severe adverse event data were “collected only for the first 57 days of the study.” In the event NIAID determined the adverse event was related to vaccination, further data were collected through day 181 — even though “blood was drawn at day 365 also.”
“Why were SAEs not collected through day 365 for everyone? That is how you learn what the SAEs related to a vaccine actually are,” Nass said.
Data from the U.S. government’s Vaccine Adverse Event Reporting System (VAERS) as of Sept. 27 indicate 2,115 reports of adverse events related to MVA-BN, including 19 reports for people under 18.
According to Managed Healthcare Executive, “Bavarian Nordic is preparing for a clinical trial to assess the safety of MVA-BN in children 2 to 12 years of age.”
The trial will be partially funded by the Coalition for Epidemic Preparedness Innovations, which previously announced its intention to develop “pandemic-busting vaccines in 100 days.”
