Boston Health Officials Respond to Mpox Cases

Boston and state health authorities are keeping a close eye on a rise in mpox cases, previously known as monkeypox. They’ve initiated new vaccination campaigns aimed at protecting vulnerable populations.

Mpox is considered an infectious disease that spreads through direct contact with the bodily fluids of an infected individual. Symptoms typically include a painful, itchy rash that can present as pimples, blisters, or scabs, along with fever, headache, and muscle aches. Officials highlighted that gay and bisexual men, particularly those with multiple sexual partners, are at the highest risk.

Currently, the Boston Public Health Commission reassures the public that there’s no widespread health threat posed by mpox at this moment. From August 1, 2025, to March 31, 2026, there were 77 recorded cases in Massachusetts. While this number shows an increase from 23 cases during the same period last year, it’s still significantly lower than the over 400 cases reported during the major outbreak in 2022.

Interestingly, only two cases emerged in the state from April 1 to May 28, according to a representative for the Massachusetts Department of Public Health. Dr. Kathryn Himmelstein, the medical director of the Boston Public Health Commission’s Infectious Disease Bureau, noted that while recent months have shown an increase, the numbers don’t approach the levels seen in 2022. “We’ve had a rise, certainly not back to 2022 levels, but an increase compared to the very low baseline we had in 2023 and 2024,” she explained.

Mpox transmission can occur through close physical contact, whether sexual or otherwise, as well as direct contact with contaminated objects. The Boston Public Health Commission pointed out that the virus doesn’t spread through incidental contact, like brushing past someone in a crowded space.

A recent study suggests there may be more asymptomatic infections than previously assumed. In light of the recent uptick in cases, Boston will be launching several mpox vaccination clinics this summer. These clinics will be accessible to everyone, regardless of insurance status, and aim to provide vaccines at little to no cost. The first clinic is scheduled to coincide with the city’s Pride flag raising on June 1.

This two-dose vaccine has been reported to be around 80% effective in preventing illness and can also help reduce the severity of symptoms. There are two clades of the virus, with clade I mostly found in Central Africa and clade II concentrated in West Africa. The cases currently being reported in Boston are clade II, which is generally viewed as less severe.

The international outbreak of clade II in 2022 marked the first widespread transmission of mpox outside Africa. In the U.S., cases peaked in mid-2022 but have remained around 200 or fewer per month since 2024. In Boston, the count peaked at 118 at the end of 2022.

Looking at national data, mpox cases saw a rise in October and early 2026, but have steadily declined since then. Himmelstein attributed the local increase in cases to the considerable number of unvaccinated individuals within the community. It seems that some people who are now at risk were too young for vaccination at the time when the virus first gained attention.

A lot of folks got vaccinated back in 2022, but now there’s a larger group of unvaccinated people, including those who have aged into adulthood and are increasingly susceptible to mpox. This could explain the current situation, she remarked.

In addition to the city’s upcoming clinics, mpox vaccinations are also available at Mass General Hospital, Boston Medical Center, and Fenway Health. Furthermore, some pharmacies within the city have started to offer the vaccine as well.