FDA authorizes EUA for monkeypox vaccine to increase supply

Photo: Pramote Polyamate/Getty Images

The U.S. Food and Drug Administration has issued an emergency use authorization for the JYNNEOS vaccine, allowing healthcare providers to use the vaccine by intradermal injection for those 18 and older who are at high risk for monkeypox infection.

This will increase the total number of doses available for use by up to five-fold, according to the FDA.

The EUA also allows for use of the vaccine in people younger than 18 determined to be at high risk of monkeypox infection. In these individuals JYNNEOS is administered by subcutaneous injection.

FDA Commissioner Dr. Robert M. Califf said in a statement that the agency’ decision was spurred by the continued spread of monkeypox, which is outpacing the current vaccine supply.

“The FDA quickly explored other scientifically appropriate options to facilitate access to the vaccine for all impacted individuals,” he said. “By increasing the number of available doses, more individuals who want to be vaccinated against monkeypox will now have the opportunity to do so.”

WHAT’S THE IMPACT

JYNNEOS, the Modified Vaccinia Ankara (MVA) vaccine, was approved in 2019 for prevention of smallpox and monkeypox disease in adults 18 and older determined to be at high risk for smallpox or monkeypox infection. The vaccine is administered beneath the skin as two doses, four weeks apart.

For those 18 and older at high risk of monkeypox infection, the EUA now allows for a fraction of the JYNNEOS dose to be administered between the layers of the skin. Two doses of the vaccine given four weeks apart will still be needed.

There’s currently no data available to indicate that one dose of JYNNEOS will provide long-lasting protection, which will be needed to control the current monkeypox outbreak.

Data from a 2015 clinical study of the MVA vaccine evaluated a two-dose series given intradermally (between skin layers) compared to subcutaneously (underneath the skin). Those who received the vaccine intradermally received a lower volume (one fifth) than those who received the vaccine subcutaneously.

The results of the study demonstrated that intradermal administration produced a similar immune response to subcutaneous administration, meaning people in both groups responded to vaccination in a similar way. Administration by the intradermal route resulted in more redness, firmness, itchiness and swelling at the injection site, but less pain, and these side effects were manageable.

The FDA has determined that the known and potential benefits of JYNNEOS outweigh the known and potential risks for the authorized uses.

THE LARGER TREND

JYNNEOS has been tested in people with immunocompromising conditions and has been found to be safe and effective in the trials that were performed to support approval. It was initially developed specifically as an alternative for use in immunocompromised patients in the event of a smallpox outbreak.

The U.S. Department of Health and Human Services last week declared the ongoing spread of monkeypox in the U.S. a public health emergency. The administration said declaring a PHE would accelerate the federal response to the virus’ spread and communicate the seriousness and urgency of the outbreak.

The PHE declaration is in concert with the FDA’s work to explore options for getting vaccines to affected communities across the country, including using a new dose-sparing approach that could, according to HHS, increase the number of doses available by up to fivefold. 

The Biden administration has framed the action as part of a larger, comprehensive strategy to combat the monkeypox outbreak. The strategy includes significantly scaling the production and availability of vaccines, expanding testing capacity and making testing more convenient, reducing burdens in accessing treatments, and conducting outreach to stakeholders and members of the LGBTQI+ communities.

The World Health Organization declared monkeypox a public health emergency of international concern in July. The number of monkeypox cases continues to rise globally and nationally.

With the monkeypox vaccine still in short supply, the Biden administration is changing how the vaccine is administered to stretch its limited number of doses, according to NPR.

On Tuesday afternoon, federal health officials announced their decision to allow the JYNNEOS vaccine to be administered between layers of skin rather than into the fat as is currently done. By offering the shots in this way, only a fifth of the full dose is needed for each person.

Researchers from Massachusetts General Hospital in Boston found last month that there is a low risk of monkeypox transmission in healthcare settings.

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