The CDC estimates that 1.7 million gay and bisexual men are at the highest risk of contracting monkeypox.

The Centers for Disease Control and Prevention estimates that about 1.7 million men who have sex with men now face the biggest threat of monkeypox.

CDC director Rochelle Walensky told reporters Thursday that gay and bisexual men who are infected with HIV or who take medication called PREP to reduce their chances of contracting HIV face the greatest health risks from monkeypox.

“This is the population that we have focused on the most in terms of vaccination,” Walensky said.

To date, the US has received 1.1 million doses of the two-dose Jynneos vaccine, according to the US Department of Health and Human Services. The federal government has supplied more than 600,000 doses of the vaccine since May, according to HHS.

The Food and Drug Administration approved Jynneos in 2019 for adults aged 18 and over who are at high risk for smallpox or monkeypox. Jynneos, manufactured by Danish biotech company Bavarian Nordic, is the only approved monkeypox vaccine in the US.

Walensky admitted last month that demand for the vaccine has outstripped supply, leading to long queues at clinics in many cities. Sexual health clinics that serve the LGBTQ community have said the vaccination campaign should be extended to anyone who thinks they are at risk of contracting monkeypox to bring the outbreak under control.

“What we really want to do is get to the point where we can vaccinate everyone who wants it,” the doctor said. Ward Carpenter, co-director of health services at the Los Angeles LGBT Center, which administers monkeypox vaccines, screens and prescribes antiviral treatment.

“We are still not close to it. We’re really trying to focus on the people who need help the most and are most at risk. But this is not a successful public health strategy,” Carpenter said.

Monkeypox is spread primarily through skin-to-skin contact during sex among gay and bisexual men, public health officials say. About 98% of patients who provided demographic information to clinics identified themselves as men who have sex with men, according to the CDC. But public health officials have repeatedly stressed that anyone can contract the disease through physical contact with a sick person or contaminated materials such as sheets and towels.

But as the number of infections rises, the risk that the virus may begin to spread more widely increases. At least two children in the US have contracted monkeypox, likely through transmission in their families, according to the CDC.

“We’re trying to contain this disease in people who have it right now,” Carpenter said. “This is the moment, the opportunity for us to do this, because right now it’s a relatively close-knit community. If it goes outside of this community, people will completely lose the ability to contain it,” he said.

More than 6,600 monkeypox cases have been confirmed in the US as of Thursday in 48 states, Washington and Puerto Rico, according to the CDC. The actual number of infections is likely higher because people can only get tested for the virus after they develop a rash, which can take a week or more in some cases. Doctors take a swab from the rash to take a sample for analysis.

Monkeypox is rarely fatal, and so far no deaths have been reported in the US. But patients can suffer debilitating pain due to the rash caused by the virus.