Why It’s So Hard to Get a Monkeypox Vaccine Right Now

When New York City’s department of health announced on July 12 that monkeypox vaccine appointments were available in several sites around the city, demand was so high that the scheduling website crashed. Every appointment was booked within hours, leaving many people unable to get shots.

Vaccine rollout wasn’t supposed to go like this. When monkeypox cases were first detected in the U.S. in May, experts were reassuring. They stressed that—unlike COVID-19 when it first emerged—monkeypox is a known threat, with existing vaccines that could be deployed as necessary.

But the reality has been messier. Vaccine supply is limited, distribution has run into roadblocks, and it has proven difficult to prioritize the highest-risk individuals for shots. The result is that, at least in certain areas, demand is overwhelming available supply.

“Everybody would like to get the vaccine, and there’s just not enough vaccine,” says Dr. Carlos del Rio, a distinguished professor in Emory University School of Medicine’s division of infectious diseases. “You have a little bit of a Hunger Games approach.”

The shortage may be surprising, since officials previously said the country has enough vaccines in the Strategic National Stockpile (SNS). But many of the stockpiled ones are the older ACAM2000 vaccine, which is approved for use against smallpox and can also be used for monkeypox. It’s a live virus vaccine containing a virus that’s related to smallpox but milder. The shot causes a temporary sore at the injection site, which—if not properly cared for—can potentially spread the virus to unvaccinated people in close contact. About 1 in 175 people who receive ACAM200 also experience swelling of the heart and surrounding tissues. Some immunocompromised people also cannot get ACAM2000.

A newer vaccine called Jynneos, which consists of two doses given four weeks apart and is approved for use against monkeypox and smallpox, is considered more appropriate for widespread use. The U.S. had only about 2,000 doses of that product in the SNS when the outbreak began—so authorities have been rushing to obtain more.

Almost 800,000 Jynneos shots could become available for use by the end of July, when the U.S. Food and Drug Administration (FDA) is expected to authorize a Danish production facility operated by manufacturer Bavarian Nordic. Some Jynneos shots were made at an already authorized third-party facility, allowing the U.S. to place immediate orders. As of July 15, more than 300,000 doses had been made available to states and local jurisdictions, according to the U.S. Department of Health and Human Services. By mid-2023, the U.S. should have nearly 7 million doses of monkeypox vaccine, officials said.

During a July 15 press briefing, U.S. Centers for Disease Control and Prevention (CDC) Director Dr. Rochelle Walensky acknowledged that vaccine shortages are “frustrating” but said the administration is actively working to increase supply. Federal health officials will send more doses to jurisdictions that are seeing rising case rates, she said. New York, California, Illinois, Florida, Georgia, and Washington D.C. have become early hotspots, together accounting for more than half of the 1,814 cases confirmed nationwide as of July 15.

Mark Levine, Manhattan borough president in New York City, says he doesn’t feel enough doses have been sent to hard-hit areas. “We’re really not getting our fair share here,” he says, noting that New York accounts for almost a third of cases nationwide. “Most people are getting turned away.”

New York City officials recently announced that they will prioritize getting first doses to as many at-risk people as possible in order to stretch supply, meaning some people may have to wait longer than the specified four weeks to get their second doses. CDC and FDA officials advised against this approach during the press briefing, noting that individuals are not adequately protected after a single dose.

Ideally, public-health officials would use what’s known as a “ring vaccination” strategy against monkeypox, prioritizing inoculation for those who are known to have had close contact with an infected person to both protect those at greatest risk and maximize available vaccine supply, says Dr. Amesh Adalja, a senior scholar at the Johns Hopkins Center for Health Security at the Bloomberg School of Public Health.

But inadequate contact tracing and testing has made it hard to identify those who are infected and exposed, says Andrew Kilianski, an emerging infectious disease expert and adjunct professor at George Mason University. National testing capacity has increased from about 6,000 tests per week early in the outbreak to 70,000 now, according to federal health officials, but Kilianski says screening is still inadequate.

“If you’re going to distribute your vaccine smartly and deliberately, you need to know who’s positive,” Kilianski says. “There’s not a lot of testing capacity, [even] for a pathogen we are ‘prepared’ for.”

Health departments in hotspots like New York City and Washington, D.C., have made vaccines broadly available to men who have sex with men and have had multiple recent sexual partners. While anyone can get monkeypox—which spreads primarily through close contact and can result in a blister-like rash as well as flu-like symptoms—men who have sex with men have accounted for the majority of U.S. cases so far.

“When you’re thinking about just vaccinating contacts, that’s not going to be as much of a demand on the supply,” Adalja says. But if anyone who meets a few wide criteria and thinks they’re at risk can get vaccinated, “the demand is much higher than the supply.”

Levine adds that in New York City, the monkeypox vaccine rollout has run into some of the same equity issues that arose during COVID-19 vaccine distribution—namely problems with online appointment scheduling.

“When you have a [scheduling] system that requires you to sit hitting refresh on a website at a given hour of the afternoon, that’s going to [benefit] younger, technologically capable people who aren’t at the kind of job that precludes them from sitting in front of a computer,” he says. “Marginalized communities and people of color are underrepresented in who’s getting vaccinated.” (Since its system crashed, New York City has switched scheduling systems and made more appointments available.)

If COVID-19 showed us anything, it’s that the “last mile” of distribution—actually getting available vaccine doses to the people who need them—must be done carefully, Kilianski says. He’d like to see more widespread testing of monkeypox, which would make it easier to tell who may have been exposed. Vaccines should also be available to high-risk people without appointments, he says.

Messaging is also important, Kilianski adds. While targeted communication to men who have sex with men has worked well, as evidenced by the high demand for vaccines, he says it’s also important to emphasize that anyone who has close contact with an infected person could catch monkeypox.

Like COVID-19 before it, monkeypox’s vaccine rollout has also shown the importance of global equity, Kilianski says. Monkeypox is endemic to certain parts of Africa—and if vaccines had been more accessible there, the global outbreak may never have happened.

“It takes a few hundred to a few thousand cases in the U.S. for us to start moving on this,” he says. “It really doesn’t have to be that way.”