Monkeypox cases are down, but concern over intradermal vaccine lingers

So in August, the FDA announced that it was issuing an emergency use authorization for the Jynneos monkeypox vaccine to be administered by intradermal injection — delivering the vaccine into the immune cells between the layers of the skin, often in the forearm, rather than a deeper injection into fat or muscle tissue in the shoulder. The method, while used for other vaccinations, had not previously been authorized by the United States for the monkeypox vaccine. It uses a smaller amount of vaccine, meaning one dose could be split among five people.

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Two months later, the outbreak appears to be waning and monkeypox vaccine appointments are more plentiful in many parts of the country than earlier in the summer, when obtaining a shot was like “winning the sweepstakes or getting concert tickets,” one recipient said.

However, the makeshift vaccination plan has not been without its downsides. The intradermal injection can leave a painful, itchy red mark for weeks, potentially worsening the stigma of an outbreak mostly affecting gay men, and it can cause long-term discoloration or scarring. The FDA’s emergency authorization of the intradermal method largely relied on a single study done in 2015, which showed that intradermal and traditional “subcutaneous” injections of the vaccine produced similar immune responses.

All of which has left some people with lingering concerns about stigma, discomfort and efficacy.

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Cooper Newnam, a 25-year-old Phoenix resident, said he skipped getting the second shot in the two-dose regimen because of concerns about the intradermal injection method. Other gay men he knew who had received their second doses in their forearms were left with a red welt, a visual reminder of the outbreak that changed how they felt at work and “made them feel sort of marginalized,” he said.

“I felt like no one told us, ‘You’re about to have a clear sign of monkeypox on your body, even though you’re being vaccinated.’ Still, to some degree it is a clear sign because the straight communities are not going to have that giant bump on their arm,” Newnam said. “It was further marginalizing.”

Max, a 36-year-old who lives in New York City, said he was worried not about the safety of the intradermal shot, but about whether it would be as effective as his first dose, which was administered via the traditional method.

“I was concerned that maybe what I was receiving — one-fifth of the dose in this different way — was perhaps not as effective as the recommended dose administered to me in my arm the first time,” said Max, who spoke on the condition that his full name not be used because of concerns about professional repercussions and the stigma associated with monkeypox.

The pain was “not horrible,” but enough to wake him in the middle of the night, he said. He found himself wondering: What “did I do to myself to need to get this?”

The intradermal injection method is “a more difficult technique to learn,” said William Schaffner, an infectious-disease specialist at Vanderbilt University Medical Center. “You have to use a smaller needle, and you have to be very deft in learning how to do that, because you don’t want to go through the skin.” Too deep, and the smaller dose won’t be enough to provide a sufficient immune response, he said.

Should I still be worried about monkeypox?

Top federal health officials, including Rochelle Walensky, the director of the Centers for Disease Control and Prevention, wrote in an opinion piece published in the New England Journal of Medicine last week that “despite limited clinical evidence,” data suggested that the intradermal shots would produce an equal immune response “for preventing monkeypox infection and illness.”

The CDC and the FDA are “committed to performing the studies needed to assure that our expectations are borne out,” the article said. In the meantime, people at high risk of infection are recommended to receive both doses, and vaccine manufacturers are urged to test the method to “expand our understanding” of it.

But even the manufacturer of the vaccine used in the United States has expressed concern to the Biden administration about the intradermal method. “We do have some reservations … due to the very limited safety data available,” Bavarian Nordic chief executive Paul Chaplin wrote in a letter sent to top administration officials and obtained by The Washington Post in August. Chaplin said “it would have been prudent” to conduct further studies before switching up the vaccination strategy.

In its response, the FDA told Chaplin that the continued spread of the virus “necessitated that FDA vigorously explore all available vaccine options to provide protection for the population at risk.”

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As the FDA began looking into the intradermal method, it found that it would be an “effective strategy” with “an acceptable safety profile,” a top U.S. health official said in an interview, speaking on the condition of anonymity to speak candidly about the administration’s response to the outbreak.

“It was clear that there were a couple of trade-offs,” the official said, noting the discomfort and duration of the markings at the site of the injection. Despite those drawbacks, “it was really an appealing option for us to actually be able to make vaccine available to all” who were at risk of infection, the official said, noting that the quality of the 2015 study was “really good.”

Schaffner agreed that the study was “very well done” and that there was a long history of other vaccines being administered intradermally. Still, when the FDA announced its emergency authorization, “it was a bit of a surprise to all of us,” he said, though the data of its efficacy was “very reassuring.”

Despite concerns, Schaffner said it was “absolutely” better for the vaccines to be administered intradermally than not administered at all.

Joe Wood, 34, said he still needs to get his second dose but didn’t take issue with the intradermal injection. “I trust what the CDC and FDA are saying,” he said. “Protection would be my top priority, so I’m not at all worried about getting it that way, personally.”

The CDC advises people younger than 18 and those with a history of keloid scarring — thick, raised scars — to receive the vaccine via the “standard regimen.” Concerns about discoloration or scarring are “real — we can’t trivialize it,” Schaffner said.

He wondered whether there could be processes to remove the remnants of the welts, similar to how tattoos are removed, “because it would make a lot of people happier if they don’t walk around with this mark of Cain on their forearm. I regard that as a real issue.”

Joey Uy, 25, received a second dose intradermally on Monday in New York City. “This one is definitely different from the first,” which was administered in the shoulder, said Uy, who has been wearing long sleeves to avoid scratching the injection site and bathing frequently to keep it clean.

“It’s similar to getting a mosquito bite, but three or four times worse,” Uy said. “I try not to think about it.”