Less than a week after HHS Secretary Xavier Becerra declared monkeypox a national health emergency, reports have emerged that the US plans to extend its vaccine supply by opting for a different route of administration.
Officials are expected to call for intradermal injection of Bavarian Nordic’s Jynneos vaccine — the only shot approved specifically for monkeypox in the US — as opposed to subcutaneous injection, unnamed sources told both the New York Times and Washington Post on Tuesday.
HHS did not respond to a request for comment. Becerra, FDA commissioner Rob Califf, White House monkeypox response coordinator Bob Fenton and CDC director Rochelle Walensky will participate in a White House press briefing this afternoon “to provide updates on the Monkeypox response effort.”
Daniel KuritzkesIt’s believed that administering the vaccine via intradermal injection — a process by which a vaccine is delivered directly into the skin, as opposed to under the skin — requires a smaller dose and could extend the US’ supply by five times, according to the Post. That’s because the dermis is rich in dendritic cells, which specialize in taking up foreign antigens and presenting them to the immune system to elicit an immune response, Daniel Kuritzkes, chief of infectious diseases at Brigham and Women’s Hospital in Boston, told Endpoints News.
The downside? It’s more challenging to do correctly, according to William Schaffner, a professor in Vanderbilt University’s infectious diseases division.
William Schaffner“The best example we have of doing this in a widespread fashion previously is with the, rather now old-fashioned, TB tuberculosis skin tests,” Schaffner told Endpoints News on Tuesday. “ “There are still many nurses working, and some retired, who were expert at doing this. It’s a bit of an art form. The average nurse, probably in their training may never have given an intradermal inoculation or had only very brief exposure.”
It’s much easier to stick a needle through the skin, he added, which is how the vaccine is administered currently. But correctly getting it into the skin takes technique. If it isn’t done correctly, vaccine can either leak out or make its way through the skin, where it may be less effective given the lower dose.
“The reason this isn’t employed more is that it’s not easy,” Schaffner said.
This route also requires a smaller needle, though Kuritzkes noted they are “relatively easily available.” Another potential hurdle would be getting the regulatory OK to split up the contents of a single-dose vial.
“There would need to be some either permission from the FDA or potentially some work from the company that’s producing these to demonstrate that it’s okay to go in and out of the vial several times, that you don’t risk contaminating the contents, or getting foreign material in the syringe from the stopper,” he said.
Bavarian Nordic, which manufactures the Jynneos vaccine, did not respond to an interview request as of press time. Just a few weeks ago, the US ordered an additional 2.5 million doses of the liquid-frozen vaccine. Along with two previous orders this year for 500,000 and 2.5 million doses, and an order back in 2020 for 1.4 million doses, that brings the company’s US commitment to nearly 7 million doses to be delivered throughout this year and next.
The news comes as the New York Times reports that about 20 million doses of the monkeypox vaccine have expired in the US’ national stockpile.
The US also recently acted on a $26 million option for intravenous courses of Siga Technologies’ smallpox treatment TPOXX, which could be important for patients who cannot swallow.
“These option exercises for the procurement of IV formulation of TPOXX as well as the funding of a post-marketing field study for IV TPOXX highlight the growing importance of a broad-based response to the substantial risks posed by the orthopox family of viruses, including smallpox and monkeypox,” CEO Phil Gomez said in a statement.
Monkeypox cases in the US are now approaching 9,000, according to the CDC.
While Schaffner told Endpoints back in May that he was “quite confident” public health authorities in the US, Canada and Europe would quickly bring chains of transmissions under control, he’s since changed his stance.
“Its capacity to spread has been much more vigorous than many of us anticipated when it first started to appear in the Western world,” he said.
Kuritzkes, however, maintains that a widespread vaccination campaign in the US is unlikely.
“I don’t think it’s likely that we’re going to see a vaccination campaign anything like we saw for COVID, because the vast majority of the population is not really at risk for coming in contact with monkeypox or acquiring monkeypox,” he said.
