Based on previous data from Africa, the two available vaccines are thought to be up to 85 percent effective at preventing a monkeypox infection. They can also be given up to four days after exposure to monkeypox to prevent infection, and up to two weeks after exposure to reduce the severity of symptoms in someone who is ill.

Other treatments include an antiviral drug called TPOXX that is approved to treat monkeypox in the European Union but not yet in the US, where it’s cleared only for smallpox. For US doctors to prescribe TPOXX for monkeypox, they have to apply to the CDC for the drug and then complete paperwork for each person it is given to, which means that prescriptions have been low. The CDC says it is working to reduce this red tape; patients and health care professionals have criticized the organization for not fixing this supply issue quickly enough.

If someone gets severely ill, the US CDC has said that two other treatments—a monoclonal antibody called vaccinia immune globulin and an antiviral called cidofovir—can be used. But there’s still no data on how effective either would be.

Can I Get a Vaccine Even if I Haven’t Been Exposed?

Vaccines are not yet widely available. However, if you are at a higher risk of catching monkeypox, you may be eligible for one even without having definitely been exposed.

The current outbreak is spreading predominantly among men who have sex with men (MSM). In the US, this means that MSM who have had multiple sexual partners within the last 14 days and who live in areas where monkeypox is spreading are eligible for vaccination, according to the CDC. If you think you are eligible, contact your health care provider.

Note that in some states, the eligibility criteria are wider—so check what they are where you are. In North Carolina, for example, MSM who have had multiple or anonymous sexual partners in the past 90 days are eligible, and there aren’t any area restrictions. MSM who have taken PrEP in the past 90 days or been diagnosed with a sexually transmitted infection are also eligible.

That said, be aware that you might have to wait for doses to become available. At the time of writing, shortages of supplies mean that New York City has no bookable vaccination appointments, and San Francisco has had to close its drop-in vaccination service.

In the UK, MSM who have multiple partners, participate in group sex, or attend “sex on premises” venues are being prioritized for vaccination. However, if you think you might be eligible, the National Health Service asks that you wait to be invited for vaccination—walk-in services aren’t available.

Where Did Monkeypox Come From?

While the current outbreak will be the first time many have heard of monkeypox, the virus is thought to have been infecting people for centuries, possibly even millennia. A member of the same virus family as chickenpox and smallpox, monkeypox’s first documented cases were back in 1958, when there were two outbreaks in colonies of lab monkeys being kept for research—hence the name.

This, though, is a bit of a misnomer. The virus is usually carried by rodents such as squirrels, pouched rats, and dormice, among others. Cases in the past have tended to occur near tropical rainforests in Central and West Africa, where the virus is endemic. From the 1980s through to 2010, cases in the Democratic Republic of the Congo (DRC) rose more than 14-fold, and in 2020 alone there were nearly 4,600 suspected cases of monkeypox in the DRC. There have also been more than 550 suspected cases in Nigeria since 2017. Given these numbers and how interconnected the world is thanks to air travel, the current global outbreak isn’t actually that surprising.

Where Can I Get Trustworthy Information on the Disease?

The World Health Organization, US CDC, and UK Health Security Agency have been providing regular Twitter updates on the monkeypox outbreak. Global.health—an international collaboration that provides real-time data on infectious diseases—has also created a monkeypox tracker to monitor confirmed and suspected cases as they occur. These all offer reliable information on the current outbreak.

It’s important to avoid stigmatizing those infected. One of the main falsehoods circulating is that monkeypox only affects men who have sex with men, or that this group is responsible for the outbreak. People of any gender or sexual orientation can contract the disease.

Other particularly wild mistruths include the claim that certain Covid-19 vaccines are causing monkeypox because they inject chimpanzee genomic information into your cells, that the virus is airborne, that infections are doubling every three days, that monkeypox is as deadly as smallpox, and that it is a manmade virus leaked from a lab—none of which is true.

This story was originally published on May 27, 2022, and has been updated to reflect new information.