Monkeypox vaccinations have slowed down significantly in Colorado, raising questions about how the state will reach high-risk populations that are less likely to seek out a shot.

In Colorado, daily vaccinations peaked at 1,003 on Aug. 21. So far in September, the number of doses only exceeded 300 on six days. A similar pattern is happening nationwide, with second doses now outnumbering first doses, according to the Centers for Disease Control and Prevention.

Caitlin Silverstein, immunization nurse manager at the Tri-County Health Department, said that appointments stopped filling up after Labor Day. The department offers shots at its Westminster clinic on Tuesday mornings and at its Aurora clinic on Thursday mornings.

This week, the U.S. Department of Health and Human Services allowed pharmacists to administer monkeypox vaccines, a strategy it had used to expand access to COVID-19 shots. The Colorado Department of Public Health and Environment also has started promoting same-day registration for its vaccine clinics on Twitter — something that wasn’t possible in the first weeks of the campaign, when vaccine supply was limited and appointments filled up almost as soon as they became available.

Some of the reduced urgency for vaccination may be because new monkeypox cases are declining in Colorado — 80 news cases in September compared to 157 in August — and nationwide.

But the same pattern also showed up in each new round of COVID-19 vaccines: tight supply in the beginning as those who are most interested in the shot and best able to navigate the system fight for appointments, followed by a shift to trying to persuade people who don’t have vaccination at the top of their minds.

Initially, the monkeypox vaccine was only available to people who knew they’d been exposed to the virus, and to men who have multiple male partners or anonymous partners, since that population saw early spread in the U.S. In Colorado, 94% of the people who’ve tested positive for monkeypox are male, and 77% of those who shared their sexual orientation said they were gay.

Now, people of any gender can receive the shot if they:

Have multiple or anonymous sexual partners
Had close contact with people in a venue where group sex may happen
Were diagnosed with gonorrhea or syphilis in the last six months
Have HIV
Are eligible for medication to prevent HIV infection
Have sex in exchange for money or some other form of compensation
Were in close contact with someone who has monkeypox

Mardi Moore, executive director of Out Boulder County, said many people in the affected communities don’t have a great deal of trust in the government. Access is also a problem for people living in rural parts of the state, since much of the distribution effort has been focused on more-visible gay communities along the Front Range, she said.

“If they want to increase vaccination rates, they’re going to have to talk to the community, not at the community,” she said.

At first, the group couldn’t widely promote when the state’s vaccine buses were coming, because there might only be enough doses for 25 recipients at a time, Moore said. Now that the supply is steadier, they’ve started running ads on dating apps like Grindr and Scruff to try to reach men who have sex with men in all corners of the state, she said.

“We’re reaching a population that may or may not use our services,” she said. “We’re trying to remove hurdles.”

Dr. Demetre Daskalakis, the deputy response coordinator on the White House’s monkeypox team, has urged providers to minimize invasive questions about people’s sex lives. He said the CDC had also ruled that it’s safe to get the vaccine on the upper shoulder or back, if a person is concerned that someone would see the temporary vaccination mark on their forearm, according to MedPage Today.

The state has about 14,000 doses of the Jynneos vaccine — the main option for monkeypox — on hand. The vaccine was approved as a two-dose series, and Colorado has resumed second doses after pausing them when the supply was tighter.

“We continue to see a demand for monkeypox vaccine, specifically from people who received their first dose and are now able to get their second dose,” a statement from the state health department said.

The vaccine buses have been visiting locations along the Front Range, focusing on universities, bars and nonprofits that work with LGBTQ people. Local health departments and some community health centers also are offering the shots in Adams, Arapahoe, Archuleta, Boulder, Chaffee, Denver, El Paso, Gunnison, Jefferson, La Plata, Larimer, Lincoln, Montezuma, Rio Grande, Summit and Weld counties.

Initially, information about how well the vaccine worked was limited. The Jynneos shot was developed for smallpox but was believed to offer some protection from monkeypox, based on studies finding that people immunized with older versions of the smallpox vaccine had a lower risk of developing monkeypox in countries where it periodically spills over to humans.

The first real-world data on effectiveness found that men who were eligible for the vaccine, but didn’t get it, were about 14 times as likely to be infected with monkeypox as men who received it, according to the CDC. It’s possible that some of the difference could have been behavioral, if men who sought out the vaccine were more likely to limit their partners or take other precautions.

The people who’ve been vaccinated aren’t necessarily from the ethnic groups that have been most affected by the virus. In Colorado, almost 72% of the people who have received monkeypox vaccines are white, though only about 46% of people with known infections are. Hispanic Coloradans account for about 35% of cases, but have received only 11% of vaccines. Black Coloradans are similarly underrepresented, with about 10% of cases and 5% of shots.

The same disparity has come up around the country. In the week of Sept. 11, 47% of those testing positive for monkeypox were Black, 27% were white and 23% were Latino, according to the CDC.

More than half of the almost 484,000 people who received a vaccine and have ethnicity data reported were white, however. About 22% were Hispanic and only about 12% were Black.

The state health department said it is partnering with leaders in the most-affected communities to get information about the vaccines to people in a way that will resonate with them.

“We hold regular meetings and work with health care providers, local public health agencies, community-based organizations and other trusted messengers to ensure communities of color and other marginalized and underserved populations have access to vaccines through a distribution strategy that prioritizes equity and those at highest risk,” the department said in a statement.

Moore said Out Boulder County has worked with the local health department and groups serving the Latino community and people with disabilities to distribute COVID-19 vaccines, so some partnerships were already in place when monkeypox arrived.

This time, they worked with the Boulder County AIDS Project, since a disproportionate number of people who’ve gotten monkeypox also have HIV, and even visited places where people working as escorts tend to be, she said. So far, 464 people have gotten vaccinated at four mobile clinics they hosted.

“We have been saving lives for a few years together,” she said.

Some men, particularly those who aren’t out to everyone in their lives, aren’t comfortable giving their names and other identifying information and don’t want it to show up in their immunization records, Moore said. There are good reasons to ask about sexual orientation and gender identity, so the state can figure out if it’s reaching the people most in need, but the community needs to be comfortable with how that data’s used, she said.

“The real marketing is, ‘Am I going to be served as a human being, and is my private stuff going to stay private?’” she said.

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