Monkeypox cases slow down nationally and in Philly, but authorities warn that the outbreak isn’t over

The rise in monkeypox cases in Philadelphia and nationwide has slowed in recent weeks, but experts caution it is too soon to tell if the current outbreak is under control.

New cases have been trending downward nationally since mid-August, the latest Centers for Disease Control and Prevention data show. Just last week, the White House noted the rate of new cases was slowing in the parts of the country hardest hit by the virus so far.

New cases are also declining in Pennsylvania and New Jersey, according to a recent CDC analysis and local data. The Pennsylvania Department of Health attributed the dip, which is modest compared with other states, to greater public awareness and increased availability of vaccines.

In Philadelphia, new weekly cases peaked at the end of July and have declined each of the last two weeks. The Philadelphia Department of Public Health said it’s too soon to say whether the downturn in cases is more than temporary.

“It’s still hard to say if we’re seeing continued declines,” said James Kyle, a spokesperson for the health department, in an email.

» READ MORE: Here’s how to find monkeypox vaccines in Philly, Pa., N.J.

Testing likely dropped over Labor Day weekend, Kyle noted, because some of Philadelphia’s outpatient sites weren’t open. Health officials won’t know for sure that cases are trending in the right direction for another two weeks, when more test data are available.

At a news conference Sept. 7, federal health officials voiced confidence in the improving trends.

“We are encouraged by the progress we’re making right now,” said Demetre Daskalakis, the deputy coordinator of the White House national monkeypox response.

Eradicating monkeypox may not be realistic, though.

“Our goal is to really control this outbreak in the U.S.,” Daskalakis said.

Monkeypox, first identified in 1958, circulates regularly in parts of Africa. The lack of vaccination and treatment for monkeypox elsewhere in the world leaves open the possibility of future outbreaks, said Michael LeVasseur, a Drexel epidemiologist.

“Until we handle monkeypox and the global inequalities, the outbreak has once again shown there’s always an opportunity for it to pop up again,” he said.

The virus has primarily infected gay, bisexual, and trans men who have sex with men, and sex appears to be a significant source of transmission.

A recent CDC survey of men who have sex with men found almost half of respondents had cut back on either their number of sex partners, one-time sexual encounters, or sex with partners met through dating apps or sex venues.

Behavior, as much as vaccination, seems to be playing a role in the decline in new cases, said Stuart Isaacs, the dean of animal research at University of Pennsylvania’s Perelman Medical School.

Whether the virus expands beyond men who have sex with men will be an indicator to watch, Isaacs said.

In Philadelphia, fewer than a dozen of the city’s 420 cases were identified among women, as of Sept. 13.National data for the week of Aug. 20 showed women accounted for about 3% of cases.

» READ MORE: How do you get monkeypox? Sex guidelines are under debate.

Why monkeypox has yet to significantly spread beyond men who have sex with men isn’t completely clear.

One factor appears to be a relatively small number of men who regularly have sex with multiple partners. A CDC model released last week estimated that, while one-time partnerships accounted for just 16% of the sex between men on any given day, those instances were likely responsible for 50% of monkeypox cases.

Jeffrey Klausner, a doctor and expert in sexually transmitted diseases at the University of Southern California’s Keck School of Medicine, noted that women generally haven’t been as exposed to monkeypox.

“They’re at much lower risk,” he said, due in part to a lack of frequent sexual interactions with people at higher risk.

» READ MORE: Monkeypox vax has disproportionately gone to white Philadelphians. This clinic sought to balance that.

The future of monkeypox depends on administration of vaccine, and its effectiveness, too.

“If we slack up with vaccinations, we’ll see the numbers going back up again,” said Kevin Burns, executive director of Action Wellness, a health-care organization with a focus on chronic illness that is partnering with the city to host vaccination clinics at its West Philadelphia location every Friday in September and October.

In Philadelphia, racial disparities remain between the people catching monkeypox and those getting vaccinated.

Monkeypox’s spread among specific groups will be another factor to watch to determine the course of the outbreak.

“I’d probably want to see those case counts disaggregated by race and age group before celebrating a victory over monkeypox,” LeVasseur said.

About 54% of all vaccine doses in the city are going to white people, though they account for 20% of cases. Black Philadelphians have received about 26% of doses but account for 60% of monkeypox cases.

The number of vaccine doses administered declined the last two weeks of August but began to rebound last week, according to Philadelphia’s data. That doesn’t reflect a drop in demand, city health officials said.

“We see it as being related to our efforts to create more equitable distribution points,” Cheryl Bettigole, Philadelphia’s health commissioner, said in a statement last week, “which is more time consuming but, we hope, more effective in the end.”

In Pennsylvania, about 45% of monkeypox cases are among Black residents, with 38% reported among white people. Reporting on the race of Pennsylvania’s vaccine recipients outside Philadelphia, though, is so poor the state Health Department isn’t reporting it.

Also uncertain is how effective the shots are. The estimated efficacy of the vaccine, JYNNEOS, is based more on laboratory and animal testing than with patients, and now more than 70% of all vaccine shots are doses smaller than originally recommended to stretch the supply. Health officials have said the smaller doses can be just as effective.

Watching the effectiveness of vaccines, Isaacs said, particularly after more people have had the recommended two-dose series, will help determine what presence monkeypox will have in the coming months.

“I don’t have a crystal ball,” Isaacs said. “The optimistic viewpoint in me is we still could potentially get control of this outbreak.”