It has been two years since the World Health Organization declared a global health emergency over an outbreak of mpox, a disease endemic to Africa that had spread to scores of countries. Now, in the summer of 2024, a deadlier version of the infectious disease has spread from the Democratic Republic of Congo to other African nations, the strain that originally hit the United States has shown signs of a resurgence, and this week the Centers for Disease Control and Prevention (CDC) issued a new alert on mpox to health care providers.

But while the American public quickly learned about the disease during the summer of 2022, as the number of cases declined and media attention waned, much of that knowledge appears to have been lost, according to new survey data from the Annenberg Public Policy Center of the University of Pennsylvania.

In a nationally representative survey of about 1,500 U.S. empaneled adults conducted in July 2024, the policy center finds that knowledge about mpox -- which increased from July to August 2022 -- has declined, along with fear of the disease (which was previously called monkeypox). This wave of the Annenberg Science and Public Health (ASAPH) knowledge survey finds that:

• Only 1 in 20 Americans (5%) are worried about contracting mpox in the next three months, down from 21% in August 2022. In addition, fewer than 1 in 10 (9%) are worried that they or their families will contract mpox.

• Fewer than 1 in 5 people (17%) know that mpox is less contagious than COVID-19, down from 41% in August 2022. Nearly two-thirds (63%) are not sure.

• Just a third of people (34%) know that men who have sex with men are at a higher risk of infection with mpox, down from nearly two-thirds (63%) in August 2022.

• Less than half (45%) know that a vaccine for mpox exists, down from 61% in August 2022.

• Fewer people (58%) know that it's false to say that getting a COVID-19 vaccine increases your chances of getting mpox, down from 71%.

"The speed with which the public learned needed information about mpox in the summer of 2022 was a tribute to effective communication by the public health community," said Kathleen Hall Jamieson, director of the Annenberg Public Policy Center (APPC) and director of the survey. "That same expertise should now be deployed to ensure that those at risk remember mpox's symptoms, modes of transmission, and the protective power of vaccination."

Mpox outbreaks in 2024 and 2022

Discovered in 1958, mpox is a rare disease caused by an orthopoxvirus, and is a less deadly member of the family of viruses that cause smallpox, according to the CDC. Mpox may cause fever, chills, headaches, muscle aches, swollen lymph nodes, and painful rashes, particularly on the hands, feet, face, chest, mouth, or near the genitals. According to the CDC, the disease can spread through contact with infected wild animals, close (including sexual) contact with an infected individual, including contact with scabs or body fluids, or contact with contaminated materials such as towels or bedding.

The current outbreak involves a mpox strain known as clade I, which is especially virulent and dangerous to infants and children under the age of 5, according to the World Health Organization (WHO), whose director general announced this week that he was convening a panel of experts to advise him whether the outbreak should be declared a global health emergency. (The WHO called an end to the 2022 mpox global health emergency in May 2023.) The WHO says there have been over 14,000 cases this year, with at least 511 deaths, according to STAT News. In the Democratic Republic of Congo (DRC), 62% of the deaths involved children under age 5. The current subtype appears to be spread through routine close contact between individuals, though in November 2023 the WHO confirmed that this strain was also being sexually transmitted.

This deadlier strain of monkeypox has not been reported outside central and east Africa, the CDC said.

A different strain of mpox in the 2022 outbreak, known as the clade II subtype, which spread across the United States, was less deadly and largely transmitted through sexual contact, and men who have sex with men were at higher risk of the disease. That earlier strain never disappeared entirely, though new cases are at a much lower level, according to the CDC. The majority of cases are in people who are not vaccinated against mpox or have received only one of the two recommended doses, the CDC reported.

Vaccination against mpox

While knowledge concerning mpox has declined significantly, there has been a less pronounced drop in people's intentions to get vaccinated against the disease. The CDC has urged individuals to be vaccinated with two doses of the vaccine Jynneos four weeks apart -- both for people who have been exposed to mpox virus to help prevent its spread and for people with risk factors for mpox, including men who have sex with men.

An earlier APPC survey, in October 2022, found that 76% of respondents said they were "very likely" or "somewhat likely" to get an mpox vaccine if they were exposed to mpox. The current survey, in July 2024, found a slight decline -- 70% of respondents reported that they were either very/somewhat likely to get the vaccine (68%) or were already vaccinated against mpox (2%). However, 3 in 10 (30%) said they were "not too likely" or "not at all likely" to get vaccinated against mpox if exposed to the virus. In addition, 70% reported in July 2024 that they thought the benefits of vaccination against mpox outweighed the risks.

APPC's ASAPH survey

The survey data come from the 20^th wave of a nationally representative panel of 1,496 U.S. adults, first empaneled in April 2021, conducted for the Annenberg Public Policy Center by SSRS, an independent market research company. This wave of the Annenberg Science and Public Health Knowledge (ASAPH) survey was fielded July 11-18, 2024, and has a margin of sampling error (MOE) of ± 3.6 percentage points at the 95% confidence level. All figures are rounded to the nearest whole number and may not add to 100%.