Monkeypox cases in some large US cities appear to be declining, matching trends seen in Europe, and experts are cautiously optimistic the outbreak may have peaked in places hit hardest by the virus.
The optimism comes just as US officials on Friday said there’s enough of a supply of monkeypox vaccine available now – though the shots aren’t getting to some of the people who need the protection the most.
The World Health Organization said Thursday that monkeypox cases reported globally declined 21% last week, after a month-long trend of rising infections. US cases continued to rise, but some American experts believe cases are starting to decline based largely on immunity from prior infection and behavior changes as awareness of the disease has grown.
That does not mean the disease will be contained, the experts cautioned.
Since late May, the United States has recorded nearly 17,000 monkeypox cases. The outbreak, which so far has reached 80 countries outside Africa, where the virus is endemic, is largely being transmitted among gay and bisexual men.
Monkeypox, which is spread through close contact with an infected individual and the pus-filled sores common to the disease, is rarely fatal.
Rollout of Bavarian Nordic’s Jynneos vaccine has been slow because of low supplies of the shot, which is also approved to prevent smallpox. But heightened awareness of the risks and increased immunity appear to be slowing the spread.
“It’s very likely that the epidemic peaked as of last week,” said DrGerardo Chowell, an infectious disease modeler at Georgia State University School of Public Health.
Chowell’s latest model, released on Thursday, forecasts a continued slowdown in new infections in the United States over the next four weeks. The declines may not be enough to extinguish the outbreak, but they should bring infections to “very low levels”, he said.
The US Centers for Disease Control and Prevention (CDC) did not respond to requests for comment about the apparent trend.
Dr Celine Gounder, an infectious disease epidemiologist and an editor-at-large at Kaiser Health News, said she believes behavior change is driving down monkeypox transmission. But she cautioned that “people get fatigued by behavior change” and transmission may go up again, at least “until folks get two doses of the Jynneos vaccine”.
For the moment, cases appear to be dropping in some large US cities hardest hit by the outbreak.
New York City’s health commissioner, Ashwin Vasan, acknowledged the declining cases in a tweet on Thursday. “We are cautiously optimistic about this data, but will be closely following to ensure it is a sustained trend,” Vasan’s tweet read.
Likewise, data tracking monkeypox infections in San Francisco and Chicago show cases began dropping over the past few weeks.
Chicago department of public health spokesperson James Scalzitti said the city may be turning a corner but that more data is needed to confirm a downward trend.
There are other signs as well. According to data on the CDC’s website, the percentage of positive tests in public health and some commercial labs – an indicator of transmission rates – has fallen sharply, from 55% positive on 16 July to 24% on Wednesday.
Meanwhile, about 10% of monkeypox vaccine doses have been given to Black people, even though they account for one-third of US cases, according to the CDC.
The new numbers come from 17 states and two cities, and they represent the most comprehensive details available on who’s been getting the two-dose vaccines. Similar disparities had been reported previously by a few states and cities.
Experts offered several possible explanations for the disparity. It may be related to how and where shots are being offered and publicized. It may be that some Black men don’t trust doctors and government public health efforts. Or they may be less willing to identify themselves as a person who is at higher risk of catching the disease.
The gap echoes disparities seen during the Covid-19 pandemic, when certain racial groups were a disproportionately large share of cases but a smaller fraction of the people initially receiving vaccinations, said Yvens Laborde, director of global health education at Ochsner Health in New Orleans.
“If we’re not careful, the same thing will happen here” with monkeypox, he said.
Reuters and the Associated Press contributed reporting.