Mpox: what to know

This article is up to date as of April 8, 2025, and based on vaccine guidance provided by the U.S. Centers for Disease Control and Prevention (CDC). Individual states may adopt their own vaccine policies and recommendations based on local public health assessments and regulatory frameworks. For the most up-to-date information, consult your state or local health department or your health care provider.

It seems like every year a new virus or disease makes headlines: COVID-19, RSV (respiratory syncytial virus), new flu strains and even a rise in measles. Another disease to be aware of is mpox (previously known as monkeypox). Once mostly confined to parts of Africa, recent outbreaks have brought it to new regions, including the U.S., raising questions about how it spreads and who’s most at risk.

So how can people protect themselves? Let’s break it down.

In this article:

What is mpox?

Mpox is a viral infection caused by the monkeypox virus, which is in the same family as smallpox. While it’s generally milder than smallpox, it can still cause discomfort, and in rare cases, serious complications. The virus was originally found in western and central Africa, but a major outbreak in 2022 led to cases worldwide.

Why was monkeypox renamed mpox?

The name “monkeypox” may be misleading; the virus is believed to spread mainly through small rodents, not monkeys. It also carried harmful racial connotations and had been previously used in a discriminating way against certain groups. To help reduce the stigma, the World Health Organization (WHO) renamed it mpox.

Mpox symptoms: what to watch for

Mpox typically starts with flu-like symptoms and then develops into a rash. Here’s what to look for:

Early symptoms

• Fever
• Cough
• Chills
• Swollen lymph nodes
• Fatigue
• Muscle aches and backaches
• Headache
• Sore throat
• Nasal congestion

The rash

• Can appear on the hands, feet, face, chest or anus, or around the genitals
• Starts as pimples or blisters and progresses to scabs
• Can be painful or itchy

When someone is exposed to mpox, they may not show symptoms right away.

Symptoms usually appear within 21 days after exposure. During this time, the exposed person is contagious until all sores heal and new skin forms. New research suggests that people may be able to spread mpox to others one to four days before they even start showing symptoms. However, there isn’t any evidence that people who never had symptoms can spread the virus.

The Centers for Disease Control and Prevention (CDC) recommends that patients see a health care provider as soon as possible if they think they are sick with mpox. In most cases, mpox symptoms clear up on their own within a few weeks. However, in rare cases it can lead to serious complications or even death. Newborns, children, pregnant people and those with weakened immune systems – like from advanced human immunodeficiency virus (HIV) – are at a higher risk for severe mpox and its effects.

How mpox spreads

Mpox spreads primarily through close physical contact.

Person-to-person transmission

• Direct skin-to-skin contact with mpox rash, scabs or lesions around the anus or vagina
• Contact with bodily fluids from a person with mpox
• Prolonged face-to-face exposure (like kissing, hugging or breathing near someone)
• Sexual contact (mpox isn’t a sexually transmitted infection [STI], but intimate contact can play a role in transmission)
• From an infected parent to the fetus during pregnancy or to a newborn during and after birth

Contaminated objects and surfaces

Mpox can linger on clothing, towels, bedding and objects (e.g., electronics and sex toys) that have not been disinfected after use by someone with mpox.

Animals

The virus can spread through bites, scratches, urine, feces or flesh (from hunting, trapping or processing) from an infected animal. To reduce the risk, avoid contact with wild animals (living or dead) in areas where mpox is endemic. The Centers for Disease Control and Prevention (CDC) has a list of animals that can carry mpox.

Pets and humans can, in theory, pass mpox to each other, but there's no confirmed evidence of this transmission happening. Anyone who has or suspects they have mpox, should avoid close contact with animals, including pets, to prevent possible transmission. If a pet is thought to be infected with mpox, call a veterinarian for further guidance. For more details, visit the CDC for signs and symptoms in pets.

About the mpox vaccine

Jynneos is the recommended vaccine for the current mpox outbreak in the U.S. It’s given in two doses, spaced four weeks apart, either before or after exposure. It's about 75 percent effective after one dose and 80 to 86 percent after two doses.

Who needs the mpox vaccine?

Although anyone can get mpox, the CDC doesn’t currently recommend routine vaccination for the general public. Instead, vaccination is recommended only for certain higher-risk groups:

• LGBTQ+ individuals with an additional risk factor: Gay, bisexual and other men who have sex with men who were recently diagnosed with an STI (chlamydia, gonorrhea or syphilis) or who have more than one sexual partner.
• Contact with an infected person: Someone who has mpox or a recent sexual partner diagnosed with mpox.
• Travelers to high-risk areas: Check the CDC’s website for countries with ongoing outbreaks.
• People engaging in high-risk sexual behaviors: Having multiple sexual partners, visiting commercial sex venues (bath houses or sex clubs) or engaging in sex related to a large event (raves or festivals) in areas with ongoing mpox cases. 
• Occupational risk: for exposure to orthopoxviruses (certain laboratory and health care workers).

Vaccine side effects

Side effects usually appear soon after vaccination, but some people might not experience any at all.

Injection site side effects may include the following:

• Skin redness (erythema)
• Pain
• Skin swelling caused by fluid buildup
• Itchiness
• Darkened patches or spots on the skin (hyperpigmentation)
• Thickening or hardening of the skin (induration)

Whole-body side effects may include the following:

• Fatigue
• Headache
• Muscles aches and pains
• Nausea
• Chills
• Fever

According to the CDC, getting an mpox infection following two vaccine doses is rare. If it does happen, the infection is usually milder. There is a small chance someone will have a severe allergic reaction to Jynneos, so be sure to check the full ingredient list.

Ways to help protect against mpox

• People at risk should get vaccinated.
• Avoid close contact with people who have mpox.
• Wash hands regularly with soap and water.
• Disinfect shared surfaces and personal items.
• See a health care provider if symptoms appear.

The CDC has guidelines on cleaning and disinfecting when someone has mpox. Anyone with mpox or taking care of someone who has it should wear protective gear like face masks and gloves and use antibacterial sprays to help prevent the spread of the virus.

What to do if someone gets mpox

Most people with mpox recover in two to four weeks without intervention. In the meantime, a few simple precautions can help prevent the virus from spreading to other people:

• Monitor symptoms and rest at home.
• Wash hands often, especially before and after touching the rash.
• Disinfect frequently touched surfaces.
• When around others, cover lesions and wear a mask.
• Avoid scratching the rash.
• Keep the infected area clean and dry.
• Isolate from others until fully recovered.