Student pharmacist Charles Liu administered a dose of the mpox vaccine at a Los Angeles County Department of Public Health clinic in West Hollywood, California, last August.

Mario Tama/Getty Images

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Mario Tama/Getty Images

Student pharmacist Charles Liu administered a dose of the mpox vaccine at a Los Angeles County Department of Public Health clinic in West Hollywood, California, last August.

Mario Tama/Getty Images

A dozen people fell ill with mpox in Chicago in early May, prompting the Centers for Disease Control and Prevention to warn doctors of a potential resurgence of mpox.

For those who were watching mpox closely, the rise in cases in the United States came as no surprise. There had been new cases recently reported in Europeand US health officials had warned that low MPox vaccination rates in many parts of the country were leaving people at risk particularly vulnerable.

« We’ve been beating the drum on the possibility of an increase in the number of mpox cases for months, » says Dr. Demetre Daskalakis, Mpox’s deputy national response coordinator at the White House. « But it wasn’t until the cases were reported in Chicago that people started saying ‘Oh my God, we’re at risk of recovery.' »

The Chicago epidemic has now grown more than 30 cases of mpox. While these numbers are far lower than last summer, they show that mpox has never completely disappeared.

Health officials say conditions in the US are ripe for a summer surge, if no action is taken to avoid it.

Low vaccination rates

More than half a million people at risk live in the areas with low vaccination rates, according to CDC. This puts them in danger of large and prolonged outbreaks that could last for months if mpox reappears.

During the US outbreak that began last spring, most mpox cases occurred in gay, bisexual, and other men who have sex with men. “This is mostly moving through close skin-to-skin contact, often in the context of sexual activity and often related to sexual activity between men,” says Daskalakis.

Cities like Jacksonville, Florida, Memphis, Tennessee, Cincinnati, Baltimore, Houston and Dallas are in counties where many at risk are not vaccinated, according to a CDC analysis. Other cities, including San Francisco, New York and Washington, DC, are in places with high vaccination rates, where mpox is more likely to be quickly contained if it reappears.

Overall, the CDC data proves it only about 23% of the 1.7 million high-risk people in the United States were fully vaccinated with two doses of the JYNNEOS vaccine. The disease disproportionately affects black and Latino men, which they account for about two thirds of US cases.

Recent studies found that getting two doses of vaccine is more protective than one. However « even among those who received their vaccinations last summer, [many] people who got the first dose of the vaccine never came back for the second dose, because they thought we were done with the epidemic,” once the number of cases declined last year, he says dr. They are Titansassistant professor of medicine and infectious disease specialist at Emory University.

Preventive immunity only partially protects

New evidence also shows that people with previous immunity, through vaccination or recovering from an infection, can get mpox again.

Many people in recent mpox clusters in Chicago and abroad in France they were fully vaccinated. That doesn’t mean vaccination isn’t helpful, Daskalakis says. Evidence so far shows that comprehensive vaccination is somewhere in between 66% AND 86% effective. to prevent infection and, anecdotally, new cases of mpox in fully vaccinated people have not been serious. “They just have very low grade infections, some with almost no symptoms,” he says, “If it doesn’t prevent the infection, it prevents a lot of the bad stuff that happened in the summer of 2022.”

While the US has seen few deaths from mpox, it can cause serious illness. « It’s still a disease that can be disfiguring. It can cause severe pain, and for immunocompromised people, it can even be fatal. It’s not a trivial event, » says Titanji.

As Pride month begins, health officials are urging revelers to promote good health. “Pride is an opportunity to reach people and prevent impacts,” Daskalakis says. Those who are eligible for the mpox vaccination should receive their two doses. Everyone, including those who have had mpox before, should be aware of the risk. « If you have a funny rash, it could be mpox, so go get tested, » he says, adding that tests are much more plentiful and easier to get than last summer.

From Daskalakis’ perspective, a storm appears to be brewing. Low vaccination rates, previous immunity that is only partially protective, and warm-weather holidays could combine to provide opportunities for mpox to spread, but there are also ways to limit the impacts of that storm. “Models are an attempt to predict the future, and action is our ability to change the future,” he says. Improving vaccination rates and awareness among people at risk could prevent a widespread summer surge.