A particularly deadly form of mpox, formerly called monkeypox, has led to more than 48,000 cases and more than 1,100 deaths in Africa this year. The Biden administration has donated one million doses of the vaccine to affected countries.
But in the United States, mpox vaccines are out of reach for many people who need them.
In the 2022 outbreak that reached this country, doses of the mpox vaccine, Jynneos, were made available for free from the federal stockpile. That arrangement ended in April, when the vaccine became available commercially.
But insurance companies do not yet cover the vaccine or, if they do, reimburse only a tiny fraction of the cost. Some young gay or bisexual men hesitate to use insurance, because they are not out to their families.
And some people at high risk of mpox, including those with H.I.V., are less likely to have any form of insurance at all.
“This is a massive bump in the road, and especially because it’s happening in the middle of deep concern about another outbreak,” said Dr. Stacey Trooskin, executive medical officer of the Mazzoni Center, a large sexual health clinic that serves the L.G.B.T.Q. community in Philadelphia.
The virus circulating in Africa has not yet reached the United States. Still, the outbreak overseas has led to a rise in the number of Philadelphia residents seeking the vaccine.
But at nearly $300 per dose, the clinic cannot afford to absorb the cost of immunizing them for free. And private insurance companies are not required to cover Jynneos for free until Jan. 1 (sooner if an employer-sponsored insurance plan begins earlier).
That timeline is “deeply disappointing,” Dr. Trooskin said. “Our patients need and deserve access to vaccine now.”
There are two genetically distinct forms of mpox: Clade I, seen mainly in the Democratic Republic of Congo and other Central African countries, and Clade II, which caused the worldwide outbreak in 2022, mostly among gay and bisexual men.
Clade I mpox is typically acquired from consumption of or contact with infected animals, and kills as many as 6 percent of those infected. It is most dangerous for children under 15.
A new subtype called Clade Ib that surfaced last year is capable of sustained human transmission. This subtype cropped up in heterosexual women and men — in many cases prostitutes — in parts of Congo, and in children in Congo and Burundi.
These discrepancies may be happenstance rather than the result of true differences in the viruses, said Christina Hutson, a microbiologist at the Centers for Disease Control and Prevention.
“I don’t think it’s a genetic feature of the virus,” she said. “I think it’s more of environment that is driving the transmission.”
In Congo, heterosexual transmission of Clade Ib was a key factor in mining towns along the border, where sex work is common. The average age among cases is older than 20 years.
Scientists have also found Clade Ib cases in Congo and Burundi, where the virus spread without sexual contact — in households between adults and children, and among children who do not live in the same household.
Children under 15 account for about half of the cases in Burundi, but they tend to be mildly affected.
“At the very least, what the data should tell us right now, and should suggest to us, is we can’t think of Clade Ib as only being something that is going to transmit between adults, that children can be infected,” said Jason Kindrachuk, a virologist at the University of Manitoba who has been studying the outbreaks in Congo and Burundi, along with scientists in those countries.
“We need to address the extent of nonsexual contact transmission for Clade Ib,” he said.
Many cases in children were reported in internal displacement camps, where people are clustered together with poor sanitation, hygiene and health care access — a “worst case scenario for a virus that is now able to spread with more sustained human transmission,” Dr. Kindrachuk said.
Because conditions in the United States are starkly different from those in Congo, the C.D.C.’s modeling studies suggest that Clade I mpox is unlikely to affect large numbers of Americans, and particularly children.
Unlike American children, those in Congo are weakened by other illnesses and food insecurity, and are in poorer health overall. Many gay and bisexual American men have already had the disease or have been vaccinated against it, Dr. Hutson said.
Still, the country has recorded nearly 2,400 cases of Clade II mpox so far this year, compared with fewer than 1,000 at this time last year.
The C.D.C. recommends Jynneos for adults who risk sexual exposure to mpox, and for certain health care workers.
A single dose is moderately effective against infection, but two doses are needed for robust protection, according to the C.D.C. The agency does not recommend boosters.
Some studies have warned of waning antibodies, but other forms of immunity to the virus are still protective. Unpublished data from a C.D.C. study in Congo suggests that immunity lasts at least five years, the agency said.
In the United States, the Health and Human Services Department shipped some vaccines left over in the stockpile to federally funded health centers, intended to be given free to uninsured people at high risk of mpox.
But the doses expired on Oct. 31, and because the vaccine is given as two doses four weeks apart, the first dose had to be administered no later than Oct. 3.
That leaves uninsured people with little recourse, including many at highest risk of severe illness from mpox.
The 2022 outbreak illustrated that people living with H.I.V. are particularly vulnerable to the disease because of their weakened immunity, said Dr. Rachel Bender Ignacio, an H.I.V. researcher at the University of Washington in Seattle.
And yet people with untreated H.I.V. were less likely to be vaccinated than others, she and her colleagues have found. “While we’re not sure why that is true, some of it certainly might be linkage to care or access to care,” she said.
Studies have shown that people are less likely to be vaccinated unless a provider suggests it. Some clinicians may hesitate to treat people with H.I.V., fearing the complications that can sometimes occur in immunocompromised people given live virus vaccines.
“But that’s not the case with this vaccine,” Dr. Bender Ignacio said. People with H.I.V. “do much worse with mpox, but they respond well to the vaccine.”
State Medicaid programs like Medi-Cal are supposed to cover the vaccine for many people who cannot otherwise afford it, but getting reimbursed has not been easy.
Josh Thorburn, who owns Eddie’s Pharmacy, which serves L.G.B.T.Q. people in Los Angeles, tried calling Medi-Cal multiple times when it did not reimburse the cost of the vaccine. Eventually, an agency manager told him to write a letter and request a formal review.
“I have wasted countless hours with Medi-Cal to resolve this issue to assist patients,” Mr. Thorburn said. “At this point I am giving up.”
“I have turned three patients away this week, and it is only Tuesday,” he added. Last week, Mr. Thorburn decided his pharmacy could no longer afford to offer Jynneos.
The state Department of Health Care Services initially told The New York Times that claims were being reimbursed.
But after reviewing documents provided by Mr. Thorburn, a spokesperson said the department was “notified by its system vendor about a technical issue regarding claims payments.”
“Claims paid incorrectly will be adjusted to reimburse the full cost,” the spokesperson said.
In an effort to protect the most vulnerable groups, the Los Angeles County Department of Public Health spent more than $75,000 from a federal grant to purchase 330 Jynneos doses. New York City also purchased doses, although city officials did not disclose details.
While people in big cities may manage to find vaccines for free at some sexual health clinics, uninsured people in other parts of the country may remain unprotected, said Jeremiah Johnson, executive director of the H.I.V. advocacy group Prep4All.
“If we are in a crisis situation, are we really going to see the kind of comprehensive coverage that we need to see?” Mr. Johnson said. “We’re concerned for uninsured people in Oklahoma or Alabama or wherever.”
Federal officials said they were aware of these challenges and were working with Jynneos’s manufacturer, Bavarian Nordic, and with insurance companies to improve access. Should mpox turn into an emergency, the national stockpile may release doses to augment the commercial supply, the H.H.S. said.
The C.D.C. has also been working on refining its messaging from 2022 for day care centers and schools, should the virus turn out to affect American children, said Dr. Nirav Shah, the agency’s principal deputy director.
“We are planning for that possibility, though we think it’s an unlikely possibility,” he said.
