This week, federal health officials approved the administration of reduced dosages of the Jynneos monkeypox vaccination via a new injectable technique to stretch the vaccine’s limited supply.
Jynneos vaccine has been in short supply for weeks because of the strong demand and the over 10,000 cases of monkeypox in the United States. Medical professionals can now administer injections at a shallower depth intradermally, in the skin’s outermost layers, with a dose that is one-fifth of the usual size, rather than subcutaneously, in the fatty layer beneath the skin.
However, there is a lack of clarity in the data on the vaccine’s efficacy, with some experts claiming that not enough is known about how the low-dose intradermal technique can alter the protection it gives in practice.
Dr. Robert Califf, the commissioner of the US Food and Drug Administration, warned on Tuesday that “there is no typical assessment of this vaccine,” even at the initial dosage size. Since there had been no large-scale outbreaks of smallpox or monkeypox to test it, approval for emergency use relied on studies of immune responses rather than clinical results.
Califf made this claim in a series of tweets on Thursday, saying that the new vaccination schedule will help more people get vaccinated and protected.
By allowing this previously authorized application of an approved medicine, he explained, the FDA is checking that “strong standards for safety, immunological response, and manufacturing quality” are being met.
The White House referenced clinical research from 2015 that found people’s immune responses to vaccination were comparable whether they received two full doses subcutaneously or two doses intradermally at one-fifth the entire quantity.
The study concludes that the intradermal method “may improve the number of accessible doses in an emergency circumstance.” The United States has proclaimed monkeypox to be a nationwide public health emergency as of last week.
On Tuesday, US officials announced that the National Institutes of Health would begin a clinical trial of the vaccine to collect real-world data.
People who receive their first dose of the vaccination intradermally can choose to receive their second dose either intradermally or subcutaneously, as per the new government approach.
Worries have been raised about switching to a low-dose intradermal approach.
David Harvey, executive director of the National Coalition of STD Directors, said in a statement released on Tuesday that while they appreciate the federal government’s willingness to look for solutions to help rectify the shortage of vaccines, no effort to protect people’s health should come without proper due diligence and research.
“There has been an insufficient study on this dosage and route of administration, and we worry that it will lead individuals to believe they are safe when they are not. This method seems to be rushed forward without data on efficacy, safety, or other dosage options, and it raises red flag after red flag.”
The CEO of the vaccine’s manufacturer, Bavarian Nordic, has voiced the company’s concerns about the White House’s plan to federal officials.
“Dose-sparing strategies, such as postponing the second vaccination, have the full support of Bavarian Nordic (BN), which is committed to helping governments throughout the world contain the current monkeypox outbreak. But we have doubts about the [intradermal] method, “In a letter dated Tuesday, CEO Paul Chaplin contacted Governor Brown of California and US Secretary of Health and Human Services Xavier Becerra.
“While this dose and delivery route may seem safe at first glance, we are very concerned that individuals will be led to believe that they are safe when in fact they are not because of the lack of adequate research into these factors. This method seems to be rushed forward without data on efficacy, safety, or other dosage options, and it raises red flag after red flag.”
The CEO of the vaccine’s manufacturer, Bavarian Nordic, has voiced the company’s concerns about the White House’s plan to federal officials.
“Bavarian Nordic (BN) is committed to helping governments worldwide contain the current monkeypox outbreak and agrees with dose-sparing measures such as postponing the second vaccination. We do, however, have certain concerns about the [intradermal] method “California Governor Jerry Brown and United States Department of Health and Human Services Secretary Xavier Becerra received a letter from CEO Paul Chaplin on Tuesday.
There must be “formal clinical efficacy data”
Prevention of monkeypox by Jynneos was first evaluated in infected animals, and human antibody responses in smallpox clinical trials can be extrapolated to monkeypox.
However, there is currently a lack of information on how well the Jynneos vaccine protects against monkeypox infection, even with a subcutaneous dose, because it was originally developed to help the nation’s defense against smallpox as a bioterrorism response effort.
“However, the lack of clinical efficacy data for the monkeypox vaccination should not be seen as evidence against it. I believe it is a testament to the vaccine development efforts that we have a vaccine for monkeypox already, largely before this major outbreak occurred, “Boston’s Beth Israel Deaconess Medical Center’s Center for Virology and Vaccine Research Director Dr. Dan Barouch made this statement.
In 2019, the Jynneos vaccine was approved by the Food and Drug Administration (FDA) as a live-virus-free alternative to the traditional smallpox vaccine. Before that, the only vaccination that had been approved by the FDA to prevent smallpox was ACAM2000, made by Sanofi Pasteur Biologics. Since ACAM2000 is associated with a higher risk of adverse effects and is not advised for persons with severely impaired immune systems, Jynneos has been the vaccine of choice during the present outbreak.
According to Dr. Amesh Adalja, a senior scholar at the Johns Hopkins Center for Health Security at the Johns Hopkins Bloomberg School of Public Health, “Jynneos was a second-generation smallpox vaccine whose use case was to be a backup vaccine for individuals who could not get ACAM2000 in the event of a smallpox biological weapons attack.”
“There was never any plan to use ACAM2000 or Jynneos for monkeypox,” he emphasized. They were successful against it, but that wasn’t why they were working on it.
According to the FDA, around 400 healthy adults participated in clinical research that determined Jynneos to help prevent smallpox. Only some of them got the ACAM2000, while the others got the Jynneos.
The 85% effectiveness rate cited by the CDC for the smallpox vaccinations Jynneos and ACAM2000 in the prevention of monkeypox is based on their evaluations of their respective efficacy profiles.
Considering what we know about the smallpox vaccination and the success of Jynneos in treating monkeypox in animals, as well as the lack of clinical efficacy data, Barouch is confident that Jynneos will be very effective.
“In general,” he continued, “vaccines are usually more efficient at preventing the severe effects of the disease than preventing acquisition of infection with the pathogen.”
However, “the intricacies of it in terms of the actual numerical efficacy — and whether it will be prevention of infection or avoidance of severe disease — are not understood at this moment,” Barouch said. “I do think that high-risk folks should get vaccinated, but at this time I do not think it can give very accurate recommendations as to exactly what that protection would look like,” the author says.
The potential for dramatic enhancements to accessibility
As Stat News reported on Tuesday, Dr. Philip Krause, former deputy director of the FDA’s Office of Vaccines Research and Review, and Dr. Luciana Borio, an infectious disease physician, argued that switching to a lower dose of the Jynneos vaccine outside of a clinical trial would increase the doubts about the vaccine’s efficacy.
Lower-dose intradermal injections “make sense,” Krause and Borio concluded, “if the vaccine can be delivered at lower dosages with no danger to effectiveness.” “However, the opposite may also be true. If there is a concern about the vaccine’s efficacy, it may be best to target the males who have intercourse with several men to contain the outbreak.”
Medical personnel caring for monkeypox patients, close contacts of patients, and anyone else lucky enough to locate doses at local clinics have all received the vaccination during the epidemic. The Centers for Disease Control and Prevention (CDC) has determined that at least 1.5 million persons in the United States qualify for the monkeypox vaccine.
On Tuesday, Dr. Stacy Lane, a clinician at Pittsburgh’s Central Outreach Wellness Center, said, “We have a line out around the block” due to high demand for the monkeypox vaccine.
To aid in local monkeypox response efforts, HHS has shipped over 670,000 doses of the Jynneos vaccine from the Strategic National Stockpile.
According to the White House, “as part of the next phase of the national vaccine strategy, the SNS is prepared to send about 400,000 additional vials to states and jurisdictions.” To request extra doses earlier, “jurisdictions that administer 90% of their current vaccine supply may do so.”
With the green light for intradermal injections, “Using intradermal administration, the 400,000 vials of the vaccine in the SNS’s inventory that have been allocated but not yet delivered might provide up to 2 million doses. Vaccines that have been received by jurisdictions but have not yet been administered can also be given intradermally.”
Intradermal administration, as suggested by Lane, may “greatly improve” vaccine accessibility. She mentioned that shorter syringes, like those used in tuberculosis testing, would be required to inject the vaccine intradermally and that her clinic had already placed an order for them. She revealed on Tuesday that she had placed an order for them that afternoon before the FDA had given its approval.
According to Lane, many of her patients are concerned about contracting monkeypox, and she tells them to look at the data from the ACAM2000 vaccination as an indication of how effectively the Jynneos vaccine may protect against monkeypox.
“We are informing the public that the ACAM2000 vaccination, which was previously administered in Africa, offered roughly 85% protection against monkeypox. Since these orthodox virus families share a tendency to react similarly to treatment and the vaccine shows some promise, “- Lane declared.
She also said that the new immunization plan will not cause any alarm. They are not witnessing any vaccine hesitation at this time, she said.
Intradermal administration was also discussed by Dr. Paulette Grey Riveria as a potential method to extend availability.
Grey Riveria, a family care physician with the virtual health platform PlushCare and the state of Louisiana’s regional medical director, suggested in an email to CNN that intradermal Jynneos injections would be a good way to increase vaccination supply without jeopardizing safety.
Researchers are trying to find out if subcutaneous immune cells can stimulate an antibody response as well as or better than subcutaneous injections.