Chicago mpox epidemic raises alarm over summer spread

A cluster of mpox cases in the Chicago area, just months after the end of the public health emergency over the epidemic that began last year, has raised fears of a resurgence of infections this summer.

The US response to the 2022 mpox outbreak was hailed as a public health success, despite some initial setbacks. By early this year, enough progress had been made that the White House allowed the public health emergency to expire.

But officials with the Centers for Disease Control and Prevention (CDC) said last week that there was a “significant risk” of a resurgence of infections this summer. The warning comes days after the World Health Organization declared the infection with mpox. No longer a global health emergency.

Worryingly, investigators found that more than half of the Chicago cluster had received some level of vaccination.

Narelly Mora, an assistant research professor at the Parkinson School of Health Sciences and Public Health at Loyola University Chicago, believes the clusters may be the result of people failing to vaccinate the full schedule.

She noted that while the rate of mpox infection has dropped to a very low rate of one to three people per day in recent months, the virus hasn’t completely disappeared.

“We know that the percentage of people who want the full vaccination schedule is not that high,” Mora said. “Some of them may forget to reach the 28-day point after receiving the first vaccination where a second vaccination is required to achieve full immunity. No, it didn’t happen at all.”

The Chicago findings have prompted experts to call for more research into the effectiveness and duration of the smallpox vaccine used during last year’s outbreak.

Since there is no mpox-specific vaccination, the smallpox vaccine ACAM2000 and the new Jynneos were introduced because the two viruses are closely related.

Jynneos, given twice 28 days apart, has become the most commonly administered injection because it is generally believed to have fewer side effects.

In the early stages of an mpox outbreak, many health departments were short on ginneos supplies and were given all doses on hand without knowing when sufficient supplies would be available for a second dose. Some health departments have resorted to doing so.

Because of this situation, many people failed to get the second dose.

The difference between one dose and two doses of Jynneos is potentially very large. CDC officials told a press conference that estimates of vaccine efficacy with a single dose of Gynneos ranged from 36 to 75 percent, while efficacy from two doses ranged from 66 to 86 percent. pointed out.

Harvard Medical School professor Martin Hirsch said the difference was particularly “dramatic” among immunocompromised people, who could develop stronger immune responses than those with healthy immune systems. pointed out to be low.This is particularly alarming given what we know about U.S. vaccination rates.

“People who consider themselves to be at high risk or who are at high risk should get the first dose of the vaccine,” Hirsch advised. “According to the data I have seen in the United States, only 23 percent of those considered at risk are currently fully vaccinated.”

CDC hasn’t changed so far its recommendations Regarding the mpox vaccine schedule, it is not clear whether people who have been previously vaccinated should receive a second dose before this summer.

“CDC recommends that anyone who is at risk, has been infected, or has been exposed to mpox receives a total of two doses of the mpox vaccine,” the agency said. said when asked for comment.

Mora said people who were vaccinated on an incomplete schedule should see if a full two doses are possible. However, people who have been vaccinated for both can probably wait before inquiring about further vaccinations.

“I don’t think there’s any indication that the vaccine’s effectiveness is going to wear off any time soon,” Hirsch said. “I don’t think people who have been vaccinated should be particularly concerned unless they are at particularly high risk.”

Groups that health authorities recommend to be vaccinated include those who have been in contact with an mpox-infected person. Men who have sex with men, transgender and gender-diverse people who have had multiple sex partners within the past 6 months. immunocompromised person. People working in high-risk settings such as clinics and hospitals.

In Hirsch’s opinion, the general public can refrain from getting mpox vaccination because the risks may outweigh the benefits. He urged those with concerns to talk to their health care providers.

of Mitigation strategy Last year still applies. Wash your hands; if you are infected, clean your clothes and linens. And avoid high-risk situations where skin-to-skin contact is likely.