Two years ago, the World Health Organization (WHO) declared a public health emergency after a multi-country outbreak of mpox (formerly known as monkeypox). Now, in the summer of 2024, mpox is on the rise again. On August 14, The WHO declared a new public health emergency due to a recent outbreak in the Democratic Republic of the Congo (DRC) and other African countries.

Mpox is a zoonotic disease endemic to parts of Central and West Africa caused by the monkeypox virus (MPXV). It is spread from person to person through close contact— touching, sexual activity, or being face-to-face in close proximity with someone who has the virus—or through contact with contaminated clothing, needles, or in shared community spaces. The disease has two distinct clades (or groupings): clade I and clade II. While the spread of a strain of clade II was responsible for the 2022 emergency, the threat in 2024 comes from a mutated strain of the more deadly clade I.

While mpox has been spreading throughout the African continent for 70 years, it has been mostly doing so undetected. The current strain has an estimated fatality rate of 3.6% with nearly 20,000 cases and 600 deaths in the DRC in 2024. The current outbreak began in the DRC, and has since spread to neighboring countries, including (but not limited to) Uganda, Kenya, Rwanda, and Burundi. While the 2022 outbreak was primarily spread through sexual contact among men who have sex with men (MSM), the current wave impacts a wider demographic, including children, pregnant people, and people living with HIV who are not on treatment.

Mpox is in the same family as the smallpox virus. But while the smallpox vaccine has shown to be protective against mpox, it has largely been phased out of public health programs since the eradication of that disease in 1980. Most cases of mpox see symptoms like rashes, fever, muscle aches, and sore throat subside after 2-4 weeks, but they can persist longer in people with weakened immune systems.

Which Populations Are Most Vulnerable?

Children are particularly vulnerable to mpox due to higher risk of close contact, increased malnutrition, and the absence of the smallpox vaccination. In the DRC, children younger than 15 years old make up 66% of cases and more than 82% of deaths.

Mpox also has a significant adverse effect on pregnant people, though the current prevalence of the infection among pregnant people is unknown. The current strain of mpox has the ability to spread from mother to child during pregnancy and birth and has caused increased rates of miscarriage. Reports on the current strain and other historical cases of clade I mpox suggests that anywhere between 50-75% of pregnant people with mpox will experience miscarriage or stillbirth. People living with HIV also have a higher risk of contracting and dying from mpox. Reports indicate they die from mpox at twice the rate as the general population, particularly if their HIV remains untreated.

People seeking treatment for mpox often also face stigma and discrimination, as groups initially impacted by the virus—MSM, transgender people, gender diverse people, and sex workers—already face heightened discrimination. Addressing this stigma is critical to reaching people who may be at higher risk of infection or death.

Need for Pandemic Preparedness

Authorities in the DRC have yet to impose restrictions or lockdown orders to reduce the spread of mpox, despite the WHO declaration. This decision adds to concerns about the continued spread of the virus to and in countries where the health system is already weakened by Ebola, COVID-19, and other stressors – including the ongoing conflict in the DRC. The virus is also mutating faster than expected, and is doing so in areas where experts lack the resources to fully track the spread of the disease.

Though the recent major outbreaks are currently limited to the African continent, Sweden confirmed its first case of the clade I mpox strain on August 15. No other cases outside of the continent have been reported, but health authorities warn that more cases in people traveling from African countries are expected.

However, it is unlikely that mpox will evolve into a full-scale global pandemic in the way of COVID-19. So the primary focus of public health action in the new emergency is to end the outbreaks in the DRC and the surrounding countries. Mpox, unlike COVID-19, is not airborne over long distances, and spreads primarily through close skin-to-skin contact. Additionally, the infection causes visible skin lesions, which lessens the likelihood of people unknowingly being in close contact with those infected.

Vaccines are critical tools to end the outbreak. Unlike COVID-19, there are already multiple vaccines that protect against mpox recommended by the WHO. Yet there are challenges. These vaccines are only recommended for people who are at risk of contracting the virus, rather than for use in mass vaccination campaigns. And there are currently no doses of the vaccine available in the DRC.*

More than 380,000 doses of mpox vaccines have been promised by the United States and the European Union (EU)—roughly 15% of the doses needed to end the outbreaks in the DRC. Spain alone has committed 500,000 doses—20% of their stockpile—to combat the outbreaks, calling for other EU member states to commit the same. However, delivering the donated vaccines and purchasing vaccines from pharmaceutical companies has faced delays due to the lack of WHO approval of the available vaccinations and the lack of an emergency license to purchase and distribute doses of the vaccine.

The emergency license was secured in late August, and the first batch of vaccines was expected to arrive in the DRC on September 1. Yet these delays in the response to the outbreak have called attention to what leading African scientists say is “decades of neglect” from the global community to end the sporadic mpox epidemics since the first case was recorded in 1970. The supply of diagnostics tests in the DRC also is still insufficient, which further complicates efforts to monitor and stop outbreaks.

Distributing the donated vaccines in the DRC, as well as increasing the supply in the country and surrounding areas, is critical to slowing the spread of the outbreak. But it is essential to focus attention on populations particularly vulnerable to the disease, as well as people in displacement camps due to ongoing humanitarian crisis in the country. Long-term attention to health systems strengthening and outbreak preparedness in endemic countries also is imperative to the prevention of future mpox outbreaks.