Officials struggle over whether to allow new monkeypox vaccination strategy
WASHINGTON – It sounds like a simple solution to the monkeypox vaccine shortage: Just by changing the way it is given, the federal government could vaccinate five times as many people as there is in supply. level in hand.
But the approach — injecting one-fifth of the current dose into the skin instead of the entire dose into the underlying fat layer — isn’t quite as straightforward, experts say. And some federal officials are concerned about changing the method without more research, though Dr. Robert M. Califf, head of the Food and Drug Administration, described the proposal Thursday. is promising.
Some outside experts are also recommending caution. “From a basic science perspective, this will work,” said Dr. Jay K. Varma, director of the Cornell Center for Pandemic Response and Prevention. “But, of course, there’s a lot of things in life, in science, that we think should work, and then when we actually do them, they don’t.”
Expanding the dose of the vaccine, Jynneos, could help the federal government solve a predicament partly of its own making. Despite investing more than $1 billion in developing a two-dose vaccine to be used against both monkeypox and smallpox, the government only had 1.1 million shots on hand, in part due to delays in ordering the vaccine. goods that process large quantities of vaccines and store them in vials.
That supply is enough to feed 550,000 people, but about three times the dose needed to cover 1.6 million to 1.7 million Americans, who, according to the Centers for Disease Control and Prevention, , there is a high risk of smallpox in monkeys. Currently, the virus is spread primarily through skin-to-skin contact during sex between gay and bisexual men, the CDC said.
Some federal officials hope that by injecting a smaller dose of the vaccine between the layers of skin, called an intradermal injection, the Biden administration can stop the outbreak before it spreads more widely. .
But some experts say this approach has yet to be fully studied. They also warn that some people getting vaccinated will need training to properly inject, which could slow vaccination efforts. Otherwise, the government may end up wasting doses, failing to save them.
Intradermal injections involve guiding the needle carefully into the layers of skin, a thin space filled with immune cells. If the vaccinator goes too deep and inserts the dose into the fat, the patient may not receive enough vaccine, experts say. But if the needle is not inserted far enough, part of the vaccine can leak out.
Phil Krause, who retired as a senior FDA vaccine regulator last year and worked on the agency’s licensing of Jynneos. “If you ask for this to be done nationwide with millions of doses, it’s very easy to go wrong in administering the vaccine.”
Methods on the other hand have a track record. It was used in polio vaccination campaign when dosage has been limited, as well as for rabies and tuberculosis skin tests.
Things to know about monkeypox virus
What is monkeypox? Monkeypox is a virus similar to smallpox, but the symptoms are less severe. It was discovered in 1958, after an outbreak of disease in monkeys kept for research. The virus is mainly found in parts of Central and West Africa, but in recent weeks it has spread to dozens of countries and infected tens of thousands of people, overwhelmingly men. same-sex sex. On July 23, World Health Organization declares monkeypox a global health emergency.
“This is not an entirely new concept,” said Dr. Anthony S. Fauci, President Biden’s chief medical adviser. “We thought of this as a strategy in case a vaccine ran out of stock years ago.”
Immunologists used special dichotomous needles in smallpox vaccination campaigns that allowed them to make intradermal injections more uniform and cheaper.
Dr. John Beigel, associate director of clinical research at the National Institutes of Health, said a government-funded study of Jynneos published in 2015 compared the intradermal injection with the standard injection and found that it activated comparable levels of neutralizing antibodies, a measure of the strength of an immune response. Intradermal injections cause more redness, swelling, and itching, but standard injections cause more pain.
Dr. Beigel says that switching to an intradermal injection method is a better option for preserving the vaccine than a single injection, as some jurisdictions currently do, because research has shown found that a single shot did not prompt an immune response that was nearly as strong.
“One dose is unlikely to be effective,” he said, adding that the intradermal injection method “is an acceptable way.”
Although the 2015 trial involved hundreds of participants, some experts noted that it was a single study that was limited in what it measured. NIH researchers plan to test the strategy in the skin for Jynneos in an experiment is expected to start in a few weeks. But results aren’t expected until late fall or early winter, and that plan is being worked on right now.
Dr. H. Clifford Lane, clinical director of Dr. Fauci’s National Institute of Allergy and Infectious Diseases at the NIH, said while researchers were able to gather insights by tracking people vaccinated, a traditional clinical trial would provide a clearer picture.
“I can understand doing it as long as I understand why it is done,” he says of the intradermal penetration strategy. “The question is: How can we extend the current supply without significantly affecting efficiency?”
Another question is how effectively the vaccine will work. It was licensed in 2019 for use against both monkeypox and smallpox after studies showed it caused a stronger immune response than an earlier vaccine. Federal officials said the drug itself was approved because it compared favorably to an even earlier vaccine.
Monkeypox is rarely fatal, and no deaths have been reported in the United States. Symptoms usually resolve within two to four weeks. But with the outbreak spiraling from eight cases reported at the end of May to 7,510 nowThe administration is trying to improve vaccination rates and the availability of tests and treatments.
So far, the outbreak has been almost entirely confined to men who have sex with men, with those with multiple sexual partners considered to be at particular risk. But 5 cases involving children have been reported so far On Friday, the Illinois Department of Public Health announced that an adult who works at a day care center has tested positive. with monkeypox and the children and other staff there were screened.
Thursday’s public health emergency declaration allows the federal government to speed up monkeypox investigations and approve grants, but does not invoke the FDA’s emergency powers. Changing the injection mode will require a second type of emergency declarationgiving the Food and Drug Administration more time to issue an emergency use authorization.
Federal regulatory agency can release product emergency authorization when they believe the potential benefits outweigh the potential risks. Early in the coronavirus pandemic, the Trump administration issued the same kind of emergency declaration, allowing the FDA to make a Covid-19 vaccine available to Americans months before regulators issued full approval. enough.
Dr. Califf, FDA commissioner, said on Thursday that regulators will continue to ensure vaccines are distributed safely and effectively. Regulators will likely decide in the next few days whether to implement an intradermal penetration strategy, he said, but it “is currently looking good” – a comment some outside experts have said. said seems to have come before the consideration of career managers.
Emily Cochrane and Tracey Tully contribution report.