WASHINGTON — It seemed like a simple solution to the monkeypox vaccine shortage: By simply changing the way the dose is injected, the federal government could vaccinate five times as many people with supplies.
But the approach — injecting a 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 concerned about changing the method without more research, even though the head of the Food and Drug Administration, Dr. Robert M. Calif, on Thursday called the proposal promising.
Some outside experts are also appealing for caution. “From a basic science perspective, this should work,” Dr. JK Verma, director of the Cornell Center for Epidemic Prevention and Response. “But, of course, in life, in science, there are a lot of things that we think should work, and then when we actually do them, they don’t.”
By increasing the dose of the vaccine, Genios could help the federal government solve a plight partially of manufacturing its own. Even though it invested more than $1 billion to develop a two-dose vaccine to use against both monkeypox and smallpox, the government only has 1.1 million shots, partly because the bulk of the vaccine stock is processed into vials. Ordering to do was slow.
That supply is enough to cover 550,000 people, but nearly three times as many doses are needed to cover the 1.6 million to 1.7 million Americans who, according to the Centers for Disease Control and Prevention, are at high risk of monkeypox. Huh. The CDC has said that for now, the virus is primarily spreading between gay and bisexual men through skin-to-skin contact during sex.
Some federal officials are hoping that by injecting a small dose of the vaccine between layers of skin, called an intradermal shot, the Biden administration could reduce outbreaks before spreading more widely.
But some experts argue that this approach has not been studied enough. He also warns that some vaccinators will need training to properly deliver the shots, which could slow vaccination efforts. Otherwise, the government may waste supplements, instead of saving them.
Intradermal injection involves carefully guiding the needle into folds of skin, a thin space lined with immune cells. Experts say that if a vaccinator goes too deep and fathoms the dose, the patient may not get enough of the vaccine. But if the needle is not inserted far enough, some vaccines can leak back.
“If you’re giving a low dose and you don’t inject it into the skin properly — you may be injecting it in the wrong place — you’re not giving a protective vaccine,” Dr. Phil Krause, who retired last year as a senior FDA vaccine regulator and worked on the agency’s licensing of Jynneos. “If you ask this to be done in millions of doses across the country, it is very easy to make mistakes in the administration of the vaccine.”
On the other hand, the method has a track record. It has been used in polio vaccination campaigns when doses have been limited, as well as for rabies and tuberculosis skin testing.
What’s to know about the 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 in monkeys kept for research. The virus was found mainly in parts of Central and West Africa, but in recent weeks it has spread to dozens of countries and infected thousands of people, including more men who have sex with men. Is. On 23 July the World Health Organization declared monkeypox a global health emergency.
“This is not a completely new concept,” said President Biden’s chief medical adviser, Dr. Anthony S. Fauci said. “We were thinking about this years ago as a strategy in the face of a shortage of vaccines.”
Vaccinators have used special bifurcated needles in smallpox vaccination campaigns, allowing them to perform intradermal injections more evenly and inexpensively.
An associate director of clinical research at the National Institutes of Health, Dr. John Beigel said a government-sponsored study from Genos published in 2015 compared the intradermal approach with the standard injection method and found that it triggered comparable levels of neutralizing antibodies, a measure of the strength of the immune response. There is more redness, swelling and itching than the intradermal method, but the standard injection was more painful.
Dr. Beigel said that switching to the intradermal method of preserving the vaccine was a better option than just giving a shot, as some jurisdictions are now doing, because research has shown that one shot provides an immunity. Doesn’t indicate nearly as strong of a reaction.
“One dose is unlikely to be effective,” he said, adding that the intradermal method “is an acceptable way to go.”
Although the 2015 trial involved hundreds of participants, some experts note that it was a single study that was limited in measuring it. NIH researchers were planning to test an intradermal strategy for Genos in a trial that begins in a few weeks. But the results weren’t expected until late fall or early winter, and that plan is up in the air right now.
Dr. H. Clifford Lane, clinical director of Dr. Fauci’s National Institute of Allergy and Infectious Diseases at the NIH, said that while researchers can gain insight by following people who have been vaccinated, a conventional clinical trial would provide a clearer picture. .
“I can understand this as long as it is very clear why this is being done,” he said of the intradermal strategy. “The question is: how can we increase the current supply without compromising on effectiveness?”
Another question is how well the vaccine will actually work: It was licensed for use against both monkeypox and smallpox in 2019 after studies showed it produced a stronger immune response than the earlier vaccine. was provoked. Federal officials said the drug itself was approved because it was compared to an earlier vaccine.
Monkeypox is rarely fatal and there have been no deaths in the United States. Symptoms usually resolve within two to four weeks. But with the outbreak now rising to 7,510 from eight reported cases at the end of May, the 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 who have multiple partners who are considered to be at particular risk. But with five cases involving children so far, the Illinois Department of Public Health announced on Friday that an adult working at a day care center had tested positive for monkeypox and that children and other staff members were being screened. was being
Thursday’s declaration of a public health emergency allowed the federal government to expedite monkeypox investigations and approve grants, but did not enforce the FDA’s emergency powers. Changing the injection mode would require another type of emergency declaration, giving the Food and Drug Administration more leeway to issue emergency use authorizations.
Federal regulators may issue emergency authorizations of products 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 several months before regulators issued full approval.
FDA Commissioner Dr. Calif said on Thursday that regulators will continue to ensure that the vaccine is delivered safely and effectively. He added that regulators will probably decide in the next few days whether to go with the intradermal strategy, but it is “looking good right now” — a comment that some outside experts said seemed ahead of deliberations by carrier regulators.
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Emily Cochran and Tracy Tully contributed reporting.
(This story has not been edited by seemayo staff and is published from a rss feed)