A second Maine resident has contracted monkeypox, the painful but usually non-fatal infectious disease that has been spreading throughout the world and now has been found in all but three U.S. states.

The second case was confirmed Monday in a Penobscot County man, said Dr. Nirav Shah, the director of the Maine Center for Disease Control and Prevention. The first case, announced on July 22, was a York County man.

There are almost certainly going to be more cases in the weeks ahead, Shah said.

“Additional cases of monkeypox in Maine are a risk,” he said on Maine Public’s “MaineCalling” radio show on Monday. “They are likely.”

Monkeypox isn’t new. It was first discovered in lab monkeys in 1958, with the first human case detected in the Congo in 1970. It is in the same family as the virus that causes smallpox. Researchers developed a monkeypox vaccine in 2019, and it’s already in production.

However, Shah said availability of the vaccine is very limited – Maine only has about 300 doses now.

On Monday, Maine ordered another 440 doses, its full allotment, from the federal government, but due to the continuing scarcity, it is limiting access to the vaccine to those with known exposures to someone who has contracted the virus or who is at high risk of contracting it.

Although anyone can contract this once rare African virus, those currently at the highest risk for monkeypox are gay and bisexual men who have sex with men, Shah said. That is why the Maine CDC is working closely with partner organizations serving these communities to help educate and even treat those most at risk. Risk isn’t limited to gay and bisexual men, that’s just the community where the virus has been spreading.

Unlike coronavirus, which is easily transmissible, monkeypox spreads largely through prolonged, skin-to-skin contact, including sex, though it is not considered a sexually transmitted disease. Its symptoms include fever, fatigue and muscle aches accompanied by an often painful rash and blisters.

Researchers believe smallpox treatments may be effective against monkeypox. Even untreated, however, the global monkeypox fatality rate remains low, 3-6 percent of the cases, according to the World Health Organization. As of July 29, there were 5,189 cases in the U.S., nearly doubling the total from one week earlier, according to the U.S. CDC.

Last week, the WHO declared monkeypox to be a global health emergency. In the U.S., the Biden administration has yet to decide whether to label the spread of monkeypox as a national health emergency, although it has ordered millions more vaccine doses and ramped up testing capacity.

In New York, which has the most cases of any state, Gov. Kathy Hochul declared monkeypox to be a statewide disaster emergency last Friday in hopes of scoring more vaccines from the federal government. New York City Mayor Eric Adams followed suit Monday by declaring a separate citywide state of emergency.

Federal and world health officials do not consider monkeypox to pose the kind of public health risk that COVID-19 does because of how it is spread, its low fatality rate, and the existence of an effective vaccine. Shah noted, however, that the monkeypox virus, like the coronavirus that causes COVID-19, could evolve over time.

Transmission of COVID-19, meanwhile, remains relatively stable in Maine even as the latest variant BA.5 has been spreading rapidly elsewhere. The current seven-day average for new cases is about 215, according to Maine CDC, almost identical to what it was this time last month.

Hospitalizations have been steady as well. As of Monday, there were 136 patients hospitalized with COVID-19 in Maine, 12 of them in critical care. Since July 1, the total has fluctuated between a low of 110 and a high of 143. The last time hospitalizations dipped below 100 was on April 19.

Across the U.S., meanwhile, hospitalizations from COVID-19 have been creeping up. According to the U.S. CDC, there are about 40,000 patients on average in the hospital each day, compared to just under 30,000 one month ago. Deaths are still averaging more than 400 per day.

Shah said the second vaccine booster that has been offered to people over the age of 50 and those who are immune compromised is being reformulated before it is offered to younger people to make it more effective at dealing with the latest variation of COVID-19.

“The booster landscape has been shifting and changing quite a lot lately,” Shah told “Maine Calling.”

The updated Moderna and Pfizer boosters should be rolling off manufacturing lines in September and available to people over the age of 12 – and maybe even as young as 5 years old – by October, Shah said. But those eligible for a second booster now should get them and not wait, he said.

Staff Writer Eric Russell contributed to this story