Monkeypox Vaccine Being Offered in US: Who Should Get It?

The monkeypox outbreak has spread to 81 countries where the virus doesn't normally circulate with more than 29,800 cases around the world. The U.S. has reported the most cases of monkeypox globally, with more than 8,900 cases in 49 states, the District of Columbia and Puerto Rico. President Joe Biden's Administration declared the outbreak a public health emergency last week.

Vaccines will play a crucial role in stemming the outbreak, but there's limited supply and growing demand in the U.S. NBC News previously reported that there have been a number of missteps with the rollout, from waiting until June to order more vaccines for the national stockpile, despite the outbreak beginning in May, to not allocating enough vaccine to areas where it's spreading the most.

As of last Thursday, when the outbreak was deemed a public health emergency, the U.S. had ordered 6.9 million doses of the Jynneos vaccine, the only one approved by the U.S. Food and Drug Administration for monkeypox. So far, the U.S. has distributed at least 600,000 of the 1.1 million doses currently available of Jynneos. A shipment of another 150,000 doses are expected to arrive this month, according to the Department of Health and Human Services, NBC News reported.

Here's what to know about vaccines and the monkeypox outbreak.

Is there a vaccine for monkeypox? Can I get one now?

There are two vaccines used in the U.S. to prevent smallpox and monkeypox, but they are not available to the general public.

“(The smallpox vaccine) is only available through the CDC, which maintains a stockpile, so the vaccine would really only be deployed by CDC in specific circumstances that they deem appropriate,” Dr. Daniel Uslan, co-chief infection prevention officer for UCLA Health and clinical chief of the UCLA Division of Infectious Diseases, told TODAY. “It’s not the kind of thing you can go to your local CVS or Walgreens and get, like a flu shot or COVID vaccine.”

People who may be exposed to smallpox or monkeypox through occupational hazards, like researchers and health care workers in certain settings, can still get smallpox vaccines. And if there’s reason to believe someone has been recently exposed to monkeypox or smallpox in an outbreak, getting them the vaccine can help prevent the infection from taking hold, Uslan said.

There are a few options available. First, there is the ACAM2000 vaccine, recommended by a CDC panel for use in those exposed to smallpox-like viruses since 2015. And, as of November 2021, the panel recommended the use of a second vaccine, Jynneos, specifically for monkeypox.

The CDC’s stockpile also contains a third smallpox vaccine, the Aventis Pasteur Smallpox Vaccine. This one is considered investigational, but could be made available under an emergency use authorization if needed, the CDC explained.

The CDC currently recommends that people who've been exposed to monkeypox and people who are more likely to get monkeypox get vaccinated against monkeypox.

The people most at risk of monkeypox in the current outbreak are:

  • Close contacts of people with monkeypox

  • People who had a sexual partner in the past two weeks with monkeypox

  • People who've had multiple sexual partners in the past two weeks in an area where monkeypox is spreading

  • People whose jobs may expose them to monkeypox, like lab and health care workers

Eligibility for monkeypox vaccines may depend on where you live. For example, in New York City, any man who has sex with men, transgender or nonbinary person who's had multiple or anonymous sex partners within the past two weeks qualifies. Contact your local health department to see if you qualify for the vaccine.

The monkeypox vaccine should be administered within four days of exposure for the greatest chances of preventing illness. It can be given between four and 14 days of exposure to possibly reduce monkeypox symptoms but it may not prevent illness entirely. The vaccine isn't expected to improve symptoms if given after they start.

Will an old smallpox vaccine protect against monkeypox?

Regular smallpox vaccination in the U.S. ended in the 1970s. But a smallpox vaccine — even one you received decades ago — will likely still provide some protection from monkeypox. How much protection it might give you isn't clear yet, experts said.

"We do know that the smallpox vaccine does offer some protection against monkeypox," Uslan said.

"But that protection is likely greatest in the months to years after the smallpox vaccine is given," he said. "And, of course, we have not been giving people smallpox vaccine for many decades in this country."

Those who received a smallpox vaccine many years ago will likely still be protected against that and monkeypox "because they would have memory cells that would offer protection," Michael Gale, Ph.D., an immunologist at the University of Washington, told TODAY. These cells, which include some T cells and B cells, facilitate one part of the immune response we get from a vaccine. And the protection that memory cells provide can last for many years after getting that vaccine.

Uslan agreed: "My suspicion is that they will have some protection, but we really don't know exactly how much yet," he said.

The bottom line? Even without clear answers, "if you've had a vaccination, you should be pleased you've had one if you're at any risk of getting infected," Dr. David Heymann, infectious disease epidemiologist and former assistant director-general for health security at the World Health Organization, told TODAY.

He also emphasized that it's important to be aware of the symptoms of monkeypox, as well as your own exposure risk to prevent spread.

What's next for this outbreak?

When hypothesizing whether monkeypox could reach pandemic levels, it's important to note that monkeypox spreads differently from the coronavirus. Monkeypox virus typically only spreads through close contact and tends not to spread unless someone has symptoms.

Additionally, this is a DNA virus, meaning it won’t develop new mutations and variants the same way the RNA-based coronavirus does, Gale said.

“DNA viruses proofread when they replicate,” he explained. So the virus that causes monkeypox doesn’t undergo the same “error-prone replication” the coronavirus does, making the emergence of new and concerning variants much less likely.

And the fact that we already have vaccines that can prevent the spread of monkeypox is another point in our favor.