The World Health Organization on Wednesday declared the spread of MPOX in multiple African countries a public health emergency of international concern, the second such declaration in the past two years in response to transmission of the virus.
The latest decision came following the recommendation of a panel of experts convened to advise WHO Director-General Tedros Adhanom Ghebreyesus on the issue. It also follows from this that A similar statement Tuesday by the Africa Centers for Disease Control and Prevention.
A number of countries have reported cases of MPOX this year – both the strain that fueled a previous international outbreak, known as clade IIb, and another version of the virus that evolved through person-to-person spread, clade Ib. The latter is responsible for one of the outbreaks currently taking place in the eastern part of the Democratic Republic of Congo and has spread beyond its borders.
“The detection and rapid spread of a new strain of MPox in eastern DRC, its detection in neighboring countries that had not previously reported MPox, and the potential for further spread within Africa and beyond are of grave concern,” Tedros said at the announcement of the statement. “Alongside other outbreaks of other types of mpox in other parts of Africa, it is clear that a coordinated international response is essential to stop this outbreak and save lives.”
Mpox is caused by a virus from the same family as smallpox, a virus that was declared eradicated in 1980. The virus, believed to be transmitted by small rodents in some countries in Africa, causes painful scars when contracted by humans. People with MPOX may also experience fever, muscle aches, headaches, and respiratory symptoms. The infection is especially dangerous in young children — most deaths from MPOX occur in children under 5 years of age — and people with compromised immune systems.
A public health emergency of international concern, or PHEIC, may be declared in response to a disease event where the risk of cross-border spread is considered high and international cooperation is likely to be needed to contain the threat. In this case, cross-border transmission has already occurred several times. The declaration of a PHEIC gives the WHO Director-General the authority to issue so-called temporary recommendations – guidance to countries on the steps they should take to tackle the problem. The panel of experts, known as an emergency committee, is still working on temporary recommendations to respond to this outbreak.
Some cases in Africa – particularly in South Africa and Ivory Coast – are caused by the version of the virus that gave rise to the earlier mpox PHEIC, which ran from late July 2022 to mid-May 2023. , an evolved version of clade II- viruses, became known as clade IIb. This earlier outbreak, which involved extensive person-to-person transmission, may have begun in Nigeria as early as 2015. It was the first time that the continuous spread of MPox from person to person was recorded. This transmission mainly took place through sexual contact, where it had not previously been reported that the virus could spread.
In that outbreak, which was first detected in the United Kingdom in early May 2022, transmission occurred mainly among gay, bisexual and other men who have sex with men. It hasn’t stopped, with nearly 100,000 cases reported by 116 countries since the spread was first recognized. But in many places, the number of new infections has fallen significantly since the peak of the outbreak in the summer of 2022.
The reason for the new PHEIC is a situation that was first observed last September in the DRC, one of the countries where mpox is endemic. The version of the virus transmitted in the DRC is known as clade I. It has been found to cause more severe disease than clade II and clade IIb viruses.
Transmission of Mpox in the DRC has traditionally involved young children who become infected when they catch and handle the rodents believed to carry the virus. Infected children can also infect others within their household.
Many of the cases the DRC has reported this year – more than 14,000, with more than 500 deaths – involve this type of transmission, largely in the western part of the country.
But sexual transmission of clade I viruses has now also been observed, with an area of distribution discovered in the eastern part of the DRC, near the country’s borders with Uganda, Rwanda and Burundi. The people found to be infected in this outbreak include sex workers and their clients, as well as men who have sex with men.
Person-to-person transmission has led to changes in the virus, which is the case now called clade Ib.
The infection has spread from this part of the DRC to Burundi, Kenya, Rwanda and Uganda, where a total of around 90 cases have been reported in the past month. None of these countries have previously reported a case of MPOX.
To date, no clade 1 viruses have been detected in the United States. But the Centers for Disease Control and Prevention has urged health care providers to consider MPox if they see patients with compatible symptoms who have been in the DRC or neighboring countries in the past 21 days, and to include any samples taken for testing to file with the CDC.
Dimie Ogoinaa Nigerian infectious disease expert who first reported what was happening with the emergence of clade IIb in his home country was appointed chairman of the new emergency committee.
Ogoina said a crucial part of combating these different outbreaks will be to better understand how the virus spreads within different populations and countries so that interventions tailored to those specific situations can be introduced. One of these interventions is the use of vaccines, the global supply of which is limited. Before countries can decide how to use vaccines effectively, they need to understand how the virus is transmitted among their populations, noted Ogoina, who teaches at Niger Delta University.
“It is very important that you understand your outbreak so that you can ultimately decide which groups of people to vaccinate. And we have that gap in parts of Africa where we don’t fully understand the transmission dynamics and the risk factors for MPox,” he said.
The WHO said it has been informed that Bavarian Nordic, which makes one of the poxvirus vaccines used to protect against MPox, currently has about half a million doses on hand. And Tim Nyugen, of the WHO’s department for preparedness for major impact events, said the company has indicated that an additional 2.4 million doses of the two-dose vaccine, sold as Jynneos, could be made by the end of the year – when final purchase orders are placed. The company has said it could make another 10 million doses next year if firm orders are placed, Nyugen said.
He said the WHO is also working with KM Biologics, the maker of another vaccine known as LC16, which has not been marketed but was made for the government of Japan. Nyugen said Japan has been very generous in donating LC16 doses in the past.
The US government has already announced that it will donate 50,000 doses of vaccine from the Strategic National Stockpile to the DRC. Maria Van Kerkhove, WHO’s acting director for epidemic and pandemic preparedness and prevention, called on countries that have vaccine doses they can donate to work with the global health agency. “We need to have a good overview of what is available and how it is done [doses] could potentially be used,” she said.
The declaration of a PHEIC increases the attention this issue should receive in the capitals of the world. Sometimes it is thought that it helps raise money for a particular health problem, but that is not the case. In the previous mpox PHEIC, the WHO released a call for almost $34 million to help the country and affected countries fight the outbreak, but no donor stepped forward.
Van Kerkhove said a regional request has already been made for $15 million to help with the current response, but she warned the number will rise.
Anne Rimoin, an MPox expert at the University of California, Los Angeles, just returned from the DRC, where she spent years studying the virus. She suggested that bringing this situation under control will be a challenge, both because the conditions that lead to spillover effects – when someone contracts the virus from an animal – are poorly understood, and because of the populations in which cases occur.
“We are only picking up bits of what is actually happening because the surveillance is not robust,” Rimoin told STAT. “We are dealing with vulnerable and difficult-to-reach population groups… whatever you are talking about [infected people in] remote rural areas or men who have sex with men or sex workers.”
Many questions remain about the species that carry mpox and why spillover events are more numerous in some years than others. In recent years, there have been a large number of reported spillovers, which may be partly due to improvements in surveillance but may also represent real increases driven by yet unknown factors, she said.
“These are questions that have been unanswered for a long time, because it is very difficult to do this kind of work. I mean, it’s really a needle-in-a-haystack job,” Rimoin said.
This story has been updated with vaccine and other information.