Monkeypox Vaccine: What It Is and Who Needs One – CNET

What’s happening

Health officials are expanding access to the monkeypox vaccine to people at higher risk of catching it.

Why it matters

Vaccination could be an important step to help curb the spread of monkeypox, which may have been spreading undetected for a while and can be easily misdiagnosed.

What it means for you

Most people don’t need the monkeypox vaccine right now. But if you’ve had contact with someone who has it, or you’re in a community with higher spread, you’re eligible.

Some people are eligible for the monkeypox vaccine as US health officials and local health departments iron out the details of the rollout meant to slow the spread of the disease.

The Biden Administration last week announced it’s shipping out doses of the monkeypox vaccine, Jynneos, from a US stockpile. Shots will be distributed to communities based on need, and people who have been exposed, or believe they may’ve been exposed, will be able to get one. Some cities, including New York and Denver, already have clinics set up.

The US and other countries have an ongoing outbreak of monkeypox, a disease from the same family of viruses that causes smallpox, though monkeypox is typically much less severe. As of Wednesday, there were over 600 confirmed cases in the US (which is likely a big undercount) and the number of reported cases is expected to grow as testing and awareness increases. 

Broadening access to the monkeypox vaccine may be an important step to curb spread of a disease which may have been spreading undetected for a while, and some experts think it’s happening too late. Testing for monkeypox has been relatively sparse, and the disease has been primarily detected at sexual health clinics. This could be due to the fact monkeypox lesions can resemble those of sexually transmitted diseases, like herpes. The majority of cases are in gay and bisexual men, communities that tend to be proactive about sexual health, according to the World Health Organization’s regional director for Europe, Dr. Hans Henri P. Kluge.

“We’re sort of playing catch-up,” said Dr. Amesh Adalja, an infectious-disease expert and senior scholar at the Johns Hopkins Center for Health Security.

“If you’re not getting full capture of cases through contact tracing and you’re worried about unrecognized chains of transmission, it may be advantageous to have a broader eligibility in order to just put an end to it,” he said.

Here’s everything we know about monkeypox vaccination in the US. Also, read more about everything we know about monkeypox, including symptoms, how it spreads and more. 

Now playing: Watch this: Monkeypox Explained: What You Need to Know

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What is the monkeypox vaccine? 

The US has two vaccines that work against monkeypox in its national stockpile. Both are expected to work before a monkeypox exposure, as well as after an exposure before symptoms start. (The fact that the vaccines work post-exposure sets monkeypox apart from diseases like COVID-19.) 

Jynneos (made by Bavarian Nordic) is a new-generation vaccine approved by the US Food and Drug Administration in 2019 for monkeypox and smallpox. It’s a two-dose vaccine, with each shot given four weeks apart. It uses a weakened virus and is approved for adults 18 and older who are at high risk of getting monkeypox or smallpox.

Jynneos is the vaccine that is being shipped out and currently being used in the US monkeypox response. It’s limited in supply, but the CDC says there may be more available in the coming weeks and months. 

Jynneos is the newest monkeypox vaccine, but it’s not the only one in the US stockpile.

ACAM2000 is a second-generation smallpox vaccine that also works against monkeypox. (The two diseases are closely related and both caused by orthopoxviruses, which makes this possible.) If necessary, the US Department of Health and Human Services said it’s also prepared to ship out the ACAM2000 vaccine, which is in greater supply than Jynneos but remains a second choice in the monkeypox response because it has a side effect profile that isn’t safe for certain people.

ACAM2000 is administered differently than the typical vaccine shot we’re used to. It’s given by dipping a needle into a vaccine solution which will then be “pricked” several times on the upper arm. It will cause a localized infection (a “pox”), prompting an immune response. 

While ACAM2000 doesn’t cause smallpox, it contains live vaccina virus, which isn’t suitable for everyone. It could be unsafe for immunocompromised people, pregnant folks and those with certain heart or skin diseases.

Smallpox was declared eliminated from the world in 1980. The US stopped routine vaccination against it in 1972, though some healthcare workers or people who work in labs may have had the vaccine.  According to the CDC, ACAM2000 is a derivative of Dryvax, which helped eradicate smallpox.

A smallpox vaccine scarA smallpox vaccine scar

A smallpox vaccine scar. Jynneos, a newer-generation monkeypox and smallpox vaccine, is not the same type of vaccine as the one used to eradicate smallpox and it doesn’t leave a scar. People born before the mid-1970s might have a scar.

Picture Alliance/Getty Images

Who needs a monkeypox vaccine?

Most people don’t need a monkeypox vaccine right now. This isn’t a widespread rollout, like the kind most countries initiated for the COVID-19 vaccine. For starters, monkeypox doesn’t spread easily. You usually need to have prolonged, intimate contact with someone — think household member, sexual partner or dance partner at a club.

While anyone can catch or spread monkeypox, gay and bisexual men are making up a disproportionate number of cases in the current outbreak. Ahead of the national response, New York began offering the vaccine to people who may be at higher risk of getting it. Colorado is also operating pop-up monkeypox vaccine clinics

According to the CDC, you meet the criteria for a monkeypox vaccine if: 

  • You’re a contact of someone who has monkeypox or you were identified as possibly exposed via contact tracing. 
  • You had a sexual partner within the last two weeks who has monkeypox.
  • You’ve had multiple sexual partners in the last two weeks in an area with a high number of monkeypox cases.

If you’re concerned about monkeypox or your risk for exposure, contact your doctor or local health clinic. 

Availability and eligibility may ultimately depend on where you live and your local health department’s guidance. Adalja says the response to the current monkeypox outbreak isn’t meant to be “one-size-fits-all,” but the vaccine “should be on the table if we’re having difficulty with contact tracing,” which some experts argue is already a reality.

How effective are the vaccines? 

Because the US outbreak of monkeypox is so new, there’s no data yet on exactly how effective the vaccines will be, according to the CDC. Effectiveness of Jynneos against monkeypox is supported by animal studies, the agency says. And though it won’t be used in most cases, ACAM2000 is closely related to Dryvax, the vaccine that helped get rid of smallpox. Effectiveness for ACAM2000 is supported by animal studies as well as human clinical trials. 

While it’s not known how likely it is you’ll get monkeypox after getting vaccinated, you should still self-isolate if you develop symptoms of monkeypox, such as a rash, the CDC says. For the vaccine to be most effective post-exposure, the vaccine should be given four days after an exposure, according to the CDC. If given between 4 and 14 days post-exposure, it may not prevent infection, but is expected to reduce the symptoms of the disease, the agency says.

A computer image of a monkeypox virusA computer image of a monkeypox virus

A computer image of a monkeypox virus.

Uma Shankar Sharma/Getty Images

Why does the US have a stockpile of monkeypox vaccines? 

The US has a stockpile of Jynneos and ACAM2000 on hand not because the country was worried about an outbreak of monkeypox (which has been endemic in some African countries for years), but in case smallpox becomes a public threat again. Smallpox was declared eliminated in the 1980s, and the last natural outbreak in the US happened in the 1949s. But smallpox is usually much more severe than monkeypox, and officials worry it could be used as biological warfare. 

“The stockpile was created in the event of a biological weapons attack on the United States with smallpox,” Adalja says. In this event, health officials would not be rationing vaccines or using only the newer-generation vaccine, according to Adalja. 

“If there was a smallpox attack, we would be using whatever vaccines we have to be able to deal with it,” he added. 

The information contained in this article is for educational and informational purposes only and is not intended as health or medical advice. Always consult a physician or other qualified health provider regarding any questions you may have about a medical condition or health objectives.

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