A surge in mpox cases in the Democratic Republic of Congo (DRC) has spilled over to neighbouring countries, prompting the World Health Organization (WHO) to consider declaring a new international emergency as several nations report their first-ever cases of the virus.

WHO Director-General Dr Tedros Adhanom Ghebreyesus announced Wednesday he will convene an emergency committee “as soon as possible” to advise on whether the current mpox outbreak represents a public health emergency of international concern – the WHO’s highest level of alarm. 

“In light of the spread of mpox outside DRC and the potential for further international spread within and outside Africa, I have decided to convene an emergency committee under the International Health Regulations,” Tedros said at a press briefing in Geneva.

The potential declaration comes just over a year after WHO ended the previous global health emergency for mpox in May 2023. The earlier crisis, declared in July 2022, stemmed from a worldwide outbreak mainly affecting men who have sex with men. About 90,000 cases and 140 deaths were reported across 111 countries during that emergency.

Mpox is back

A new variant of the mpox virus, known as clade 1b, is fueling the outbreak in eastern DRC that has spread to neighboring countries. Burundi, Kenya, Rwanda and Uganda, which have never reported mpox cases before, are now seeing infections.

Mpox cases in the first half of 2024 have already matched the total for all of 2023. Since the start of the year, the Africa Centers for Disease Control and Prevention reports that 10 African Union member states have recorded over 14,000 mpox cases, with more than 450 deaths. Of these, nearly 2,750 cases have been confirmed, while the rest are suspected.

The DRC, where mpox was first detected in 1970 and remains endemic, bears the brunt of this outbreak, accounting for more than 96% of both cases and deaths. The country, then known as Zaire, has been grappling with the virus for over five decades.

The virus has reached urban areas, including Goma, a city of more than 2 million people bordering Rwanda. Other outbreak hotspots, such as the mining town of Kamituga, see frequent travel to Rwanda and Burundi. Goma hosts more than 200,000 displaced people in four camps west of the city, the capital of North Kivu province.

“There is a real risk of an explosion of the disease given the huge population movements in and out of DRC,” said Albert Massing, medical coordinator for Doctors Without Borders in DRC.

Early reports indicate clade 1b could be more lethal, with a 3% to 6% case fatality rate compared to 0.2% for clade 2, which drove the 2022-2023 global outbreak. However, health officials caution more data is needed to draw definitive conclusions.

“We don’t know if it is more severe,” said Dr Rosamund Lewis, WHO’s mpox lead. “Most of the persons affected so far have been children, who are more vulnerable, so it is still difficult to say whether this strain is less or more severe.”

The outbreak has affected diverse groups, including sex workers, students, businessmen and travelers, according to DRC health authorities. Scientists have identified mutations in clade 1b that indicate the virus now spreads exclusively from person to person, confirming sustained human-to-human transmission.

A Nature study published in June, examining 108 confirmed mpox cases near Goma, revealed unexpected trends. Unlike the 2022 global outbreak that mainly affected men who have sex with men, 51.9% of cases were female, with 29% of these being sex workers. WHO reports that while sex workers initially accounted for about a third of all cases, this proportion is declining as the virus spreads more widely in the community.

“At the moment, there is no specific information that suggests that the clade 1b is more transmissible per se,” Lewis said. She noted that the rapid spread might be due to sexual transmission rather than increased transmissibility of the virus itself.

“We know from the global outbreak that transmission through sexual networks occurs more rapidly,” she explained. “That doesn’t necessarily mean that the virus itself is more transmissible.”

Vaccines sitting in stockpiles

WHO is working to accelerate vaccine access in affected countries by initiating an emergency use listing for two approved mpox vaccines. This move aims to speed up procurement and distribution through partners like Gavi and UNICEF, while also facilitating national approvals by health authorities.

Tedros noted WHO is collaborating with affected governments, Africa CDC, the African Union, and other partners to surveil and stem outbreaks. The organization’s $15 million regional response plan is currently supported by just $1 million from its emergency fund. To the dismay of WHO officials, no funding has yet been made available at an international level.

“We’re having once again to dip into the contingency fund for emergencies to begin the response,” said Dr Michael Ryan, WHO’s emergency response chief. “It was frankly amazing to me that even in the large-scale mpox outbreak we had around the world, there was no funding made available at the international level. There must be a financial commitment to stop this virus.”

Mpox vaccines are available. Bavarian Nordic, the sole manufacturer of mpox vaccines, reported record financial results in 2023, with preliminary revenue of $1 billion, primarily driven by vaccine sales.

“The increased manufacturing capacity and broader customer base also mean that we will be able to respond to future surges in demand, following increased cases of mpox, or extraordinary governmental orders,” Bavarian Nordic CEO Paul Chaplin said in a February press release.

The company’s growth was propelled by public health preparedness actions, including several mpox vaccine orders from an undisclosed European country and 500,000 doses purchased by the United States for its national stockpile.

Despite these stockpiles, vaccine access remains limited in frontline regions. The DRC has approved two vaccines and received 50,000 doses donated by the United States, but these haven’t been deployed. Médecins Sans Frontières (MSF) reports a lack of available vaccines on the ground.

“We can only plead, like so many others, for the vaccines to arrive in the country as quickly as possible and in large quantities, so that we can protect communities in the areas most affected—particularly the most at-risk groups such as Congolese health workers, who are on the front line of the infection, as well as other at-risk groups such as sex workers and displaced people in camps,” said Massing, the group’s head of operations in DRC, this week.

At Wednesday’s Geneva press briefing, Tedros acknowledged Japan, the United States, the European Union and vaccine manufacturers for their efforts on “vaccine donations”. These vaccines have not yet reached the outbreak’s frontline.

“It’s a virus that can be contained, quite straightforwardly, if we do the right things,” said Ryan. “Countermeasures themselves, vaccines do nothing. Vaccination is what saves lives.”

Image Credits: National Institute of Allergy and Infectious Diseases.