Officials wrestle with whether to allow new monkeypox vaccination strategy

WASHINGTON. It sounded like a simple solution to the monkeypox vaccine shortage: by simply changing the way it doses, the federal government could vaccinate five times as many people with its current supply.

But the approach — putting one-fifth of the current dose into the skin instead of the full dose into the underlying fat — is actually not that simple, experts say. And some federal officials are worried about changing the method without more research, even though Dr. Robert M. Califf, head of the Food and Drug Administration, called Thursday’s proposal promising.

Some outside experts are also calling for caution. “From a basic science standpoint, this should work,” the doctor said. Jay K. Varma, director of the Cornell Center for Pandemic Prevention and Response. “But of course there are a lot of things in life and in science that we think should work, and when we actually do them, they don’t work.”

Increasing the dose of the Jynneos vaccine could help the federal government solve a predicament that was partly self-created. Even though the government has invested more than $1 billion to develop a two-dose vaccine for use against both monkeypox and smallpox, the government only has 1.1 million shots, in part because it has been slow to order large stocks of the vaccine to manufacture. vials.

That supply is enough to cover 550,000 people, but it takes about three times as many doses to reach the 1.6 million to 1.7 million Americans who are at high risk for monkeypox, according to the Centers for Disease Control and Prevention. For now, the virus is spread primarily through skin contact during sex among gay and bisexual men, the CDC said.

Some federal officials are hoping that by injecting a smaller dose of the vaccine between the layers of skin, called an intradermal injection, the Biden administration can quell the outbreak before it spreads more widely.

But some experts argue that this approach is not well understood. They also warn that some vaccinators will need training to properly administer vaccines, which could slow down vaccination efforts. Otherwise, the government may squander doses rather than save them.

Intradermal injection involves carefully inserting a needle into the layers of the skin, the thin space containing immune cells. Experts say if the vaccinator goes too deep and doses the fat, the patient may not receive enough vaccine. But if the needle is not inserted deep enough, some of the vaccine may leak out.

“If you give a lower dose and don’t inject it properly into the skin – you may be injecting it in the wrong place – you may not be giving a protective vaccine,” the doctor said. Phil Krause, who stepped down as the FDA’s senior vaccine regulator last year and worked on licensing agency Jynneos. “If you ask for it to be done across the country in millions of doses, it’s much easier to make mistakes when administering the vaccine.”

On the other hand, the method has a track record. It was used in polio vaccination campaigns at limited doses, as well as skin tests for rabies and tuberculosis.

“This is not a completely new concept,” the doctor said. Anthony S. Fauci, chief medical adviser to President Biden. “We thought of it as a vaccine shortage strategy many years ago.”

Vaccinators used special bifurcated needles in smallpox campaigns, which allowed them to give intradermal injections more evenly and cheaply.

Dr. This was stated by the deputy director of clinical research at the National Institutes of Health, John Beigel. state-sponsored study by Jynneos published in 2015 compared the intradermal approach with the standard injection method and found that it elicited comparable levels of neutralizing antibodies, a measure of the strength of the immune response. The intradermal method caused more redness, swelling, and itching, but the standard injection was more painful.

Dr. Beigel said switching to the intradermal method was a better option to save the vaccine than giving just one injection, as some jurisdictions are doing now, because studies have shown that a single injection does not elicit such a strong immune response.

“A single dose is unlikely to be effective,” he said, adding that the intradermal method “is an acceptable method.”

Although the 2015 trial had hundreds of participants, some experts point out that it was the only study that was limited in what it measured. The NIH researchers planned to test an intradermal strategy for Jynneos in trial which was supposed to start in a few weeks. But the results were not expected until late autumn or early winter, and this plan is still up in the air.

Dr. H. Clifford Lane, Clinical Director The Fauci National Institute of Allergy and Infectious Diseases at the National Institutes of Health said that while researchers could gain insight into people who received the vaccine, traditional clinical trials would provide a clearer picture.

“I can understand it if it’s clear why it’s being done,” he said of the intradermal strategy. “The question is, how can we increase current inventories without significantly compromising efficiency?”

Another question is how well the vaccine will actually work. In 2019, it was licensed for use in both monkeypox and smallpox after studies showed it elicited a stronger immune response than the previous vaccine. The drug itself was approved because it compared favorably with an even earlier vaccine, federal officials said.

Monkeypox is rarely fatal, and no deaths have been reported in the United States. Symptoms usually disappear within two to four weeks. But as the outbreak grows from eight reported cases at the end of May to 7510 nowthe administration is trying to improve vaccination rates and the availability of tests and treatments.

For now, the outbreak is almost entirely limited to men who have sex with men, with those with multiple partners considered to be at particular risk. But so far there have been five reported cases involving children. The Illinois Department of Public Health announced Friday that an adult working at a day care center has tested positive for monkeypox and that children and other staff there are being tested.

Thursday’s declaration of a public health emergency allowed the federal government to expedite its monkeypox investigation and approve grants, but did not invoke the FDA’s emergency powers. Changing the injection mode will require a second kind of emergency. declarationwhich gives the Food and Drug Administration more leeway to issue emergency use permits.

Federal Regulators may issue emergency product approvals when they believe the potential benefits outweigh the potential risks. Early in the coronavirus pandemic, the Trump administration issued a similar emergency declaration, allowing the FDA to make Covid-19 vaccines available to Americans many months before regulators issued full approvals.

Dr. Kaliff, the FDA commissioner, said Thursday that regulators will continue to ensure that the vaccine is delivered in a safe and effective manner. He said regulators will likely decide in the next few days whether the intradermal strategy should be used, but that it “looks good right now,” a comment that some outside experts said preempted career regulators’ discussions.

Emily Cochrane as well as Tracey Tully made a report.